m 


GIFT   OF 
Mrs.   A.   M.    Duperu 


SUGAK    ANALYSIS 

FOR    CANE-SUGAR    AND    BEET-SUGAR 
HOUSES,    REFINERIES    AND    EX- 
PERIMENTAL   STATIONS 

AND   AS  A 

HANDBOOK    OF    INSTRUCTION    IN    SCHOOLS    OF 
CHEMICAL    TECHNOLOGY 


BY 

FERDINAND  G.  WIECHMANN,  PH.D. 


THIRD  EDITION,  REWRITTEN 
FIRST   THOUSAND 


NEW   YORK 

JOHN  WILEY  <fc  SONS,   INC. 

LONDON:     CHAPMAN    &    HALL,    LIMITED 

1914 


Copyright,  1914, 

BY 

FERDINAND  G.  WIECHMANN,  PH.D. 


THE  SCIENTIFIC  PRESS 

ROBERT   DRUMMOND    AND  COMPANY 

BROOKLYN,  N.    Y. 


I   r 


INSCRIBED 

TO 
HIS   FRIEND 

JOSEPH  A.  DEGHUEE,  PH.D. 


M503715 


PREFACE 


IN  preparing  this,  the  third  edition  of  his  Sugar  Analysis, 
the  writer  has  endeavored  to  cast  his  material  in  a  form 
in  which  it  would  prove  most  readily  available  in  the  several 
branches  of  the  sugar  industry. 

With  this  aim  in  view  the  whole  range  of  the  subject — 
the  methods  and  means  used  in  the  analysis  of  sugar  and 
in  the  analysis  of  the  materials  used  in  sugar  production, 
have  first  been  fully  discussed,  and  then  the  specific 
analytical  control  of  cane-sugar  manufacture,  of  beet-sugar 
manufacture,  and  of  refining,  has  been  taken  up  for  detailed 
consideration. 

In  adopting  this  method  of  treatment  a  certain  amount 
of  repetition  has  been  unavoidable.  This  however  has 
been  reduced  to  a  minimum  and,  it  is  believed,  that  the 
greater  convenience  for  practical  use  thus  gained  fully 
warrants  the  procedure.  Although  the  International  Com- 
mission for  Uniform  Methods  of  Sugar  Analysis  adopted — 
in  1897 — 26.00  grams  for  100  metric  cubic  centimeters, 
at  20°  C.,  as  the  normal  sugar  weight,  yet  the  American 
sugar  industry,  to  a  large  extent,  still  retains  as  normal 
weight  26.048  grams  for  100  Mohr  cubic  centimeters. 

For  this  reason  both  standards  appear  in  this  work; 
universal  adoption  of  the  Commission's  standard  is  how- 
ever strongly  urged  as  an  important  step  towards  the 
unification  of  analytical  methods  in  the  industry.  The 


vi  PREFACE 

brief  re*sume*  of  the  Commission's  work  to  date,  will,  it  is 
hoped,  prove  of  interest. 

In  the  preparation  of  this  book  free  use  has  been  made 
of  the  publications  of  standard  authorities  and  endeavor 
has  been  made  to  give  due  credit  in  every  instance.  The 
writer  would  however  here  once  more  specifically  express 
his  obligations  to  the  work  of  Browne,  Deerr,  Herzfeld, 
Home,  Prinsen  Geerligs,  Spencer  and  von  Lippmann. 

F.  G.  W. 


TABLE   OF   CONTENTS 


CHAPTER  PAGE 

I.  PROPERTIES  OF  SUCROSE 1 

II.  INSTRUMENTS  USED  IN  SUGAR  LABORATORIES 5 

Refractometers 5 

Adjustment 9 

Refractometer  tables 10 

Balances 12 

Sugar  weights 12 

Graduation  and  calibration  of  measuring  apparatus 13 

Pipettes 13 

Burettes 13 

Flasks 13 

Hydrometers 15 

Testing  hydrometers 17 

Determination  of  the  density  of  solutions 19 

By  specific  gravity  flask 19 

pipette  and  beaker 21 

hydrometers 21 

gravimeter 22 

araeo-pycnometer 23 

glass  spheres 23 

Mohr's  hydrostatic  balance 23 

analytical  balance 24 

Calculation  of  weight  of  solids  and  liquids  from  their  specific 

gravity.  25 

Colorimeters 26 

Thermometers 27 

III.  POLARISCOPES  AND  ACCESSORIES 29 

Polarization 29 

Specific  rotation 30 

Conversion  factors 32 

vii 


viii  TABLE  OF  CONTENTS 

CHAPTER  PAGE 

Polariscopes — saccharimeters 32 

Soleil-Ventzke-Scheibler  saccharimeters 34 

Double-wedge  compensation  saccharimeters 34 

Bates'  saccharimeter , 36 

Saccharimeter  scales 37 

Adjustment  and  examination  of  saccharimeters 39 

Quartz-plates 45 

Polariscope-tubes 46 

Sources  of  light 48 

IV.  SUCROSE  DETERMINATION  BY  OPTICAL,  ANALYSIS 51 

Sampling 51 

Dutch  standard 55 

A.  Determination  of  sucrose  in  the  absence  of  other  optically 

active  substances 55 

Method  I.  With  use  of  balance 55 

Method  II.  Without  use  of  balance 59 

Coefficient  of  purity 60 

Methods  I.  II.  III.  IV 60 

Sucrose  in  fill  mass 64 

Sucrose  in  condenser,  boiler-feed,  and  waste  waters 64 

Possible  sources  of  error  in  polarization 66 

B.  Determination  of  sucrose  in  the  presence  of  other  opti- 
cally active  substances  70 

Clerget-Herzfeld   method 71 

Sucrose  and  invert  sugar 74 

Sucrose  and  dextrose 74 

Sucrose  and  commercial  glucose 74 

Sucrose  and  levulose 78 

Sucrose  and  raffinose 78 

V.  SUCROSE  DETERMINATION  BY  CHEMICAL  ANALYSIS 82 

Qualitative  test  for  sucrose 82 

Quantitative  determination  of  sucrose  as  invert  &,ugar 82 

Fehling's  solution 84 

Inversion  of  sucrose 84 

Volumetric  analysis 85 

Gravimetric  analysis 87 

Sucrose  in  condenser,  boiler-teed,  and  waste  waters 89 

Sucrose  and  invert  sugar    90 

Sucrose,  invert  sugar  and  levulose  or  dextrose 90 

VI.  SUCROSE  DETERMINATION  BY  OPTICAL  AND  CHEMICAL 

ANALYSIS 94 

Sucrose  in  presence  of  invert  sugar 94 

Methods  I.  II. .  94 


TABLE  OF  CONTENTS  ix 

CHAPTER  PAGE 

Sucrose  in  presence  of  dextrose  and  levulose 97 

Sucrose  in  presence  of  invert  sugar  and  raffinose 103 

VII.  CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE 107 

Reducing  sugars  in  general 107 

Invert  sugar 110 

Qualitative  test 110 

Quantitative  determination Ill 

a.  By  volumetric  method 112 

6.  By  gravimetric  method 114 

Water 115 

Ash 118 

Scheibler's  method 118 

Carbonization  method 119 

Analysis  of  sugar-ash 121 

Suspended  impurities 122 

Woody  fiber , 123 

Organic  non-sugar 124 

Organic  acids 125 

Nitrogenous  substances 126 

Amids  and  albumenoid  nitrogen 133 

Non-nitrogenous  substances 133 

Cellulose 133 

Gums 134 

Alkalinity  of  sugars 134 

Indicators 134 

Determination  of  alkalinity 136 

Acidity  of  sugars 140 

Sulphurous  oxide  in  sugars 141 

Qualitative  test 141 

Quantitative  determination 141 

a.  By  gravimetric  method 141 

b.  By  volumetric  method 142 

Iron  oxide  in  sugars 144 

VIII.  MATERIALS  USED  IN  THE  SUGAR  INDUSTRY 145 

Bone-black 145 

Water 145 

Carbon,  sand  and  clay 145 

Calcium  carbonate 145 

Free  lime 146 

Calcium  sulphide 146 

Calcium  sulphate 146 

Iron  and  aluminum  oxides 147 

Tri-calcic  phosphate , . .  147 


x  TABLE  OF  CONTENTS 

CHAPTER  PAGE 

Sugar  in  bone-black 148 

Organic  matter 148 

Decolorizing  power 148 

Weight 149 

Phosphoric  acid  paste 149 

Limestone 152 

Calcium  oxide 152 

Carbonic  acid  gas 152 

Coal 153 

Properties 153 

Analysis 154 

Carbon  in  ash 155 

Flue  gases 156 

Sulphur 157 

Lubricating  oils 157 

Alkalinity  and  acidity 157 

Viscosity 157 

Congelation 157 

Saponification 157 

Hydrochloric  acid 158 

Density 158 

Iron 158 

Arsenic 158 

Water 158 

Total  solids 158 

Organic  and  volatile  matter 158 

Silica 159 

Lime 159 

Magnesia 159 

Iron  and  aluminum  oxides 159 

Sulphuric  acid 161 

Chlorine 162 

Hardness 162 

Improvement  of  waters 163 

IX.  ANALYTICAL  CONTROL  IN  CANE-SUGAR  MANUFACTURE 164 

Determinations  required 164 

Sugar  cane 166 

Sucrose  in  cane:  direct  method 166 

Sucrose  in  cane:  indirect  methods 168 

Cane  fiber 169 

Available  sugar 170 

Cane-juices 170 

First  mill  juice .  170 


TABLE  OF  CONTENTS  xi 

CHAPTER  PAGE 

Mixed  juices 171 

Last  mill  and  clarified  juices 175 

Syrup •. . ; 175 

Bagasse 175 

Saturation 175 

Sucrose 176 

Fiber 176 

Water 177 

Dry  substance 177 

Filter-press  work 177 

Juices 177 

Cake 178 

Sugars 178 

Sugar 178 

Fill  mass 180 

Molasses 180 

Waters 181 

Condenser  water 181 

Waste  water 183 

Boiler-feed  water 183 

Calculations 183 

Cane  formulae 184 

Juice  formulas 185 

Sucrose-loss  formulas 187 

X.  ANALYTICAL  CONTROL  IN  BEET-SUGAR  MANUFACTURE 188 

Determinations  required 188 

Sugar  beets 190 

Fresh  cosettes 190 

Exhausted  cosettes 191 

Dry  cosettes 191 

Diffusion  and  press  juices 191 

Diffusion  waters 192 

Thin  juices,  non-saturated  and  saturated 193 

Thick  juices 193 

Press  cake 193 

Fill  mass 194 

First  products 194 

After  products 195 

Raw  sugars 195 

First  products  and  after  products 195 

Molasses 199 

Cattle  Food .  .  200 


rii  TABLE  OF  CONTENTS 

CHAPTER  PAGE 

Waters 200 

Condenser,  waste  and  boiler-feed  waters 200 

XI.  ANALYTICAL  CONTROL  IN  REFINERIES 202 

Determinations  required 202 

Density  determination  of  fill  mass 204 

Apparent  density 204 

Real  density 205 

Composition  of  fill  mass 206 

Yield  or  Rendement 209 

Hints  on  reporting  sugar  analyses 212 

Sucrose  loss 215 

XII.  RESUME  OF  THE  WORK  OF  THE  INTERNATIONAL  COMMISSION 

FOR  UNIFORM  METHODS  OF  SUGAR  ANALYSIS 217 

TABLES 237 

INDEX . .  .305 


LIST  OF  TABLES 


I.  Relation  between  specific  gravity,  degrees  Brix  and 
degrees  Baume  for  pure  sugar  solutions  from  0  to 

100  per  cent 237-250 

II.  Corrections  for  temperature  in  determinations  by  the 

specific-gravity  method 251-252 

III.  Corrections  for  temperature  in  determinations  by  the 

Brix  hydrometer 253-254 

IV.  Factors:  arranged  for  specific-gravity  determinations.  255-256 
V.  Factors :  arranged  for  Brix  determinations 257-258 

VI.  Estimation  of  percentage  of  sugar  by  weight  in  weak 

sugar  solutions 259-260 

VII.  Hundred  Polarization,  Scheibler 261-263 

VIII.  Estimation  of  percentage  of  sugar  by  weight,  Schmitz.  265-273 

IX.  Pounds  solids  per  cubic  foot  in  sugar  solutions 275-276 

X.  Factors  for  the  calculation  of  Clerget  inversions 277-278 

XL  Determination  of  total  sugar. 279-280 

XII.  Determination  of  invert  sugar,  volumetric  method ...   281-282 

XIII.  Determination  of  invert  sugar,  gravimetric  method .  .   283-284 

XIV.  Solubility  of  sucrose  in  water 285-286 

XV.  Determination  of  dextrose,  Allihn 287-290 

XVI.  Determination  of  levulose,  Honig  and  Jesser 291-292 

XVII.  Density  of  water  at  the  temperatures  from  0°  to  50°  C., 

relative  to  its  density  at  4°  C.,  Rosetti 293-294 

XVIII.  Factors,  Morse 295-296 

XIX.  Comparison  of  thermometric  scales 297-300 

XX.  Tables  for  converting  customary  and  metric  weights 

and  measures 301-303 

xiii 


SUGAR    ANALYSIS 


CHAPTER  I 
PROPERTIES  OF  SUCROSE 

SUGAR,  which  is  chemically  known  as  sucrose  or 
saccharose,  is  a  compound  of  the  elements  carbon,  hydrogen 
and  oxygen.  Its  composition  is  expressed  by  the  formula 
Ci2H220n,  showing  it  to  consist  of  42.11%  carbon,  6.43% 
hydrogen  and  51.46%  oxygen. 

It  is  a  product  of  the  vegetable  kingdom  and  occurs 
in  many  plants;  it  is  found  in  leaves,  stalks,  fruits,  seeds, 
grains  etc.  in  widely  varying  amounts.  The  only  plants 
however  which  produce  it  in  sufficient  quantity  to  serve 
as  sources  for  its  extraction  on  a  commercial  scale  are  the 
sugar  cane,  the  sugar  beet,  the  sugar  maple  and  the  palm; 
and  to  a  very  much  smaller  degree  Indian  corn  (maize)  and 
sorghum  have  also  at  times  figured  as  sources  of  supply. 

Placing  the  world's  yearly  production  of  sucrose  at 
about  16  million  long  tons,  at  present  approximately  53% 
of  this  is  obtained  from  the  sugar  cane,  and  the  greater 
part  of  the  balance  from  the  sugar  beet. 

Sugar  is  formed  in  plants  from  water  taken  from  the  soil 
and  from  carbonic  acid  gas  (carbon  dioxide)  taken  from 
the  air,  through  the  intervention  of  chlorophyll,  the  green 
coloring  matter  of  plants.  This  chlorophyll  transmutes 


2  SUGAR  ANALYSIS 

the  energy  of  sunlight  into  chemical  energy  and  this  latter 
brings  about  the  chemical  combination  of  the  carbon 
dioxide  and  the  water  to  form  sucrose.  This  reaction  is 
termed  one  of  assimilation;  oxygen  is  set  free  in  the  process. 
Baeyer  in  1870  suggested  that  the  first  step  in  this  proc- 
ess is  the  formation  of  formaldehyde  as  illustrated  by  the 
reaction, 


in  which  the  chemical  symbols  given  represent  respectively 
carbon  dioxide,  water,  formaldehyde  and  oxygen. 

It  seems  probable  that  the  formaldehyde  so  formed 
suffers  a  condensation  or  polymerization  to  CeH^Oe, 
glucose,  but  this  is  a  question  upon  which  there  is  as  yet 
a  wide  divergence  of  opinion,  some  holding  that  starch, 
others  that  sucrose  is  the  first  carbohydrate  to  be  formed; 
however  it  seems  likely  that  starch  is  an  intermediary 
product  in  the  formation  of  sucrose. 

Sucrose  is  created  in  the  leaves  of  plants  and  is  thence 
distributed  to  other  parts  of  the  plant  to  be  stored  there 
as  such,  or  transformed  into  other  substances. 

Pure  sucrose  crystallizes  in  monoclinic  crystals;  impur- 
ities however  can  greatly  modify  these  forms,  raffinose  in 
particular,  causes  a  pointed  distortion  of  the  normal  tabular 
form.  Sucrose  crystals  do  not  affect  the  plane  of  polarized 
light,  whereas  the  power  which  aqueous  sucrose  solutions 
have  of  rotating  polarized  light  has  been  made  the  basis 
of  one  of  the  most  delicate  and  accurate  methods  for  the 
determination  of  this  substance. 

Sucrose  is  soluble  in  water  and  in  dilute  alcohol,  slightly 
soluble  in  boiling  absolute  alcohol,  insoluble  in  ether. 

At  20°  C.  100  grams  of  water  dissolve  203.9  grams  of 
sucrose;  at  25°  C.  211.4  grams,  at  30°  C.219.5  grams.* 

*  For  a  detailed  statement  of  the  solubility  of  sucrose  in  water 
see  Herzf  eld's  table  in  Browne's  Handbook  of  Sugar  Analysis,  p.  649. 


PROPERTIES  OF  SUCROSE  3 

Whereas  pure  water,  of  about  20°  C.,  will  hold  in  solu- 
tion only  about  40  parts  of  sucrose,  a  beet  molasses  con- 
taining 20%  of  water  will  dissolve  50  parts,  and  a  cane 
molasses  of  equal  water  content  only  30  parts  of  sucrose. 
This  is  explained  by  Dubrunfaut,  Von  Lippmann,  Prinsen 
Geerligs  and  others  by  the  fact  that  in  beet  molasses 
the  salts  prevent  the  sucrose  from  crystallizing,  whereas, 
in  cane  molasses,  the  organic  salts  enter  into  combination 
with  the  invert  sugar,  a  constituent  of  cane  molasses, 
but  essentially  absent  from  beet  molasses,  and  that  this 
combination  of  invert  sugar  and  organic  salts  binds  a 
considerable  amount  of  water  of  hydration  and  thus  lowers 
the  amount  of  free  water  in  which  the  sucrose  would 
otherwise  dissolve. 

Sucrose  is  destroyed  by  heat.  Its  melting-point  lies 
at  about  170°  C.  If  heated  beyond  this  point  it  undergoes 
decomposition  into  a  variety  of  bodies  prominent  among 
which  is  caramel,  itself  a  mixture  of  several  substances, 
notably  of  caramelane,  caramelene  and  carameline. 

Solutions  of  sucrose  suffer  changes  even  when  heated 
only  at  100°  C.  for  some  time,  at  higher  temperatures 
the  destruction  of  sucrose  is  rapid. 

Acids,  metallic  salts  and  enzymes  invert  sucrose  solu- 
tions, that  is  to  say,  by  their  influence  the  sucrose  is  caused 
to  combine  with  water  and  is  transformed  into  invert 
sugar,  a  substance  which  consists  of  equal  parts  of  glucose 
and  fructose,  or  dextrose  and  levulose,  as  they  are  fre- 
quently termed. 

The  inversion  of  sucrose  by  acids  is  chemically  thus 
represented  : 

Invert  sugar 


dextrose  levulose 


As  stated,  by  this  transformation  the  sucrose  which  has  a 
pronounced   dextrorotation  is   changed   into    invert  sugar 


4  SUGAR  ANALYSIS 

which  has  a  levorotation,  that  is  to  say  which  turns  the 
plane  of  polarized  light  to  the  left  instead  of  to  the  right. 

Inversion  of  sucrose  can  be  effected  by  minute  amounts 
of  acids;  the  rate  at  which  the  inversion  progresses  is  always 
proportional  to  the  concentration  of  the  reacting  substance. 

Different  acids  at  a  given  temperature  have  different 
inverting  powers;  hydrochloric,  nitric  and  methyl  sul- 
phuric acids  have  the  same  inverting  power,  this  is  usually 
taken  as  the  standard.  Sulphuric  acid  has  an  inverting 
power  about  54%  of  this  standard,  oxalic  acid  about  19%, 
and  phosphoric  acid  only  about  6%.  A  rise  in  temperature 
increases  the  inverting  power  of  acids  materially.  Metallic 
salts  show  an  analogous  behavior;  as  a  rule,  the  strongest 
inverting  action  is  shown  by  the  salts  of  the  strongest 
acids. 

Invertase  is  a  white  powder  which  readily  dissolves  in 
water.  It  is  prepared  from  yeast,  and  has  a  very  powerful 
inverting  action  on  sucrose,  acting  in  this  respect  purely 
as  a  catalyser,  and  causing  the  addition  of  a  molecule  of 
water  to  each  molecule  of  sucrose. 

Sucrose  readily  forms  compounds  with  metallic  bases, 
notably  with  the  alkalis  and  with  the  alkaline  earths.  Such 
compounds  are  known  as  sucrates  or  saccharates.  Tech- 
nically the  most  important  are  the  sucrates  of  lime  of  which 
three  are  known  in  which,  respectively,  one,  two  or  three 
molecules  of  lime,  CaO,  are  combined  with  one  molecule 
of  sucrose.  The  latter  compound  is  made  in  the  process  of 
Steffens  which  is  largely  employed  in  the  desucration 
of  beet  molasses. 

Strontium  monosucrate  and  bisaccharate  are  also  well 
known,  and  in  some  countries  the  use  of  barium  is  also 
resorted  to  for  reclaiming  sucrose  from  molasses  although 
in  other  countries  its  use  for  this  purpose  is  forbidden  on 
account  of  the  poisonous  nature  of  some  of  the  barium  salts. 


CHAPTER  II 
INSTRUMENTS  USED  IN   SUGAR  LABORATORIES 

Refractometers.  Among  the  first  to  introduce  the  use 
of  the  refractometer  in  the  sugar  industry  was  Hugh  Main, 
who  in  1906  first  called  the  attention  of  the  members  of 
the  International  Commission  for  Uniform  Methods  of 
Sugar  Analysis  to  its  possibilities  in  this  connection. 

The  description  of  an  Abbe  refractometer  with  beatable 
prisms,  which  follows,  has  been  abstracted  from  a  circular 
of  Carl  Zeiss,  Jena,  a  manufacturer  of  this  form  of  refrac- 
tometer. 

The  refractive  index  nD  of  the  solution  under  examina- 
tion is  read  off  directly  from  a  graduated  circle  after  a  simple 
adjustment,  for  the  method  of  measurement  is  based  upon 
the  observation  of  the  position  of  the  border  line  of  the  total 
reflection  in  relation  to  the  faces  of  a  prism  of  flint-glass, 
into  which  the  light  from  the  substance  under  investigation 
enters  by  the  action  of  refraction. 

The  refractometer  is  essentially  composed  of  the  follow- 
ing parts: 

1.  The   double  Abbe    prism,  which   contains  the  fluid 
and  can  be  rotated  on  a  horizontal  axis  by  means  of  an 
alidade. 

2.  A  telescope  for  observing  the  border  line  of  the  total 
reflection  formed  by  the  prism. 

3.  A  sector,   rigidly  connected  with  the   telescope,  on 
which    divisions — representing    refractive    indices,    are    en- 
graved. 

5 


6 


SUGAR  ANALYSIS 


The  double  prism  consists  of  two  similar  prisms  of  flint- 
glass,  each  cemented  in  a  metal  mount  and  having  a  refractive 
index  nD  =  1.75j  the  fluid  to  be  investigated — a  few  drops, 
is  deposited  between  the  two  adjoining  inner  faces  of  the 
prisms  in  the  form  of  a  thin  stratum  (about  0.15  m.m. 
thick).  The  former  of  the  two  prisms,  that  farther  from 
the  telescope  (which  can  be  folded  up  or  be  removed), 


FIG.  1. 


serves   solely   for   the   purpose   of   illumination,   while   the 
border  line  is  formed  by  the  second  flint  prism. 

The  border  line  is  brought  within  the  field  of  the  telescope 
by  rotating  the  double  prism  by  means  of  the  alidade  in 
the  following  manner.  Holding  the  sector,  the  alidade 
is  moved  from  the  initial  position,  at  which  the  index 
points  to  no  =  1.3,  in  the  ascending  scale  of  the  refractive 
indices  until  the  originally  entirely  illuminated  field  of 
view  is  encroached  upon,  from  the  direction  of  its  lower 
half,  by  a  dark  portion;  the  line  dividing  the  bright  and 


INSTRUMENTS  USED  IN  SUGAR  LABORATORIES    1 

the  dark  half  of  the  field  then  is  the  "  border  line."  When, 
daylight  or  lamp  light  being  employed,  the  border  line, 
owing  to  the  total  reflection  and  the  refraction  caused 
by  the  second  prism,  assumes  at  first  the  appearance  of  a 
band  of  color,  which  is  quite  unsuitable  for  any  exact  process 
of  adjustment.  The  conversion  of  this  band  of  color  into 
a  colorless  line,  sharply  dividing  the  bright  and  dark  por- 
tions of  the  field,  is  the  work  of  the  compensator. 

The  compensator,  which  has  its  place  in  the  prolonga- 
tion of  the  telescope  tube  beyond  the  objective,  i.e.,  at  a 
point  between  the  objective  and  the  double  prism,  consists 
of  two  similar  Amici  prisms,  of  direct  vision  for  the  D-line 
and  rotated  simultaneously,  though  in  opposite  directions, 
around  the  axis  of  the  telescope  by  means  of  a  screw-head. 
In  this  process  of  rotation  the  dispersion  of  the  compensator 
passes  through  every  value  from  zero  (when  the  refracting 
edges  of  the  two  Amici  prisms  are  parallel  and  on  different 
sides  of  the  optical  axis)  up  to  double  the  amount  of  the 
dispersion  of  a  single  Amici  prism,  the  refracting  edges  of 
the  two  Amici  prisms  being  parallel  and  on  the  same  side 
of  the  axis.  The  above-mentioned  dispersion  of  the  bor- 
der line,  which  appears  in  the  telescope  as  a  band  of  color, 
can  thus  be  annulled  by  rotating  the  screw-head,  thereby 
giving  the  compensator  an  equal,  but  opposite,  dispersion. 
The  opposite  equal  dispersions  will  then  neutralize  each 
other,  with  the  result  that  the  border  line  appears  colorless 
and  sharply  defined. 

The  border  line  is  now  adjusted  upon  the  point  of  inter- 
section of  the  reticle  by  slightly  inclining  the  double  prism 
to  the  telescope  by  means  of  the  alidade.  The  position 
of  the  pointer  on  the  graduation  of  the  sector  is  then  read 
off  by  the  aid  of  the  magnifier  attached  to  the  alidade.  The 
reading  supplies  the  refractive  index  UD  of  the  substance  under 
investigation  itself,  without  any  computation,  and  with  a 
degree  of  exactness  approaching  to  within  about  2  units 
of  the  fourth  decimal.  Simultaneously  the  reading  of  the 


8  SUGAR  ANALYSIS 

scale  on  the  drum  of  the  compensator  enables  the  mean 
dispersion  np—nc  being  arrived  at  by  the  aid  of  a  special 
table  and  a  short  process  of  computation.  The  accuracy 
of  the  measurement  of  dispersion  is  increased  by  taking  the 
mean  of  two  readings  of  the  drum  varying  by  180  degrees. 

As  the  refractive  index  of  fluids  varies  with  their  tem- 
perature, it  is  of  importance  to  know  the  temperature  of 
the  fluid  contained  in  the  double  prism  during  the  process 
of  measurement. 

If,  therefore,  it  be  desired  to  measure  a  fluid  with  the 
highest  degree  of  accuracy  attainable  with  the  Abbe  refrac- 
tometer  (to  within  1  or  2  units  of  the  fourth  decimal  of  nD), 
it  is  absolutely  necessary  to  bring  the  fluid,  or  rather  the 
double  prism  containing  it,  to  a  definite  known  temperature 
and  to  be  able  to  control  this  temperature  so  as  to  keep  it 
constant  to  within  some  tenths  of  a  degree  for  a  period 
of  several  hours;  hence  a  refractometer  principally  required 
for  the  investigation  of  fluids  must  be  provided  with  beatable 
prisms. 

The  double  prism  is  opened  out  and  closed  up  by  means 
of  a  screw-head,  which  acts  in  the  manner  of  a  bayonet 
catch.  In  order  to  apply  a  small  quantity  of  fluid  to  the 
prisms,  without  opening  the  casing,  the  screw  is  slackened 
and  a  few  drops  of  fluid  poured  into  the  funnel-shaped 
mouth  of  a  narrow  passage.  On  again  tightening  the 
screw,  the  fluid  is  distributed  by  capillary  action  over  the 
entire  space  between  the  two  prisms.  This  arrangement 
facilitates  the  investigation  of  even  rapidly  evaporating 
fluids.  Ordinarily,  a  drop  of  moderate  size  is  applied  with 
a  glass  rod  to  the  dull  prism  surface,  the  double  prism 
being  opened  out  for  the  purpose.  The  prisms  are  then 
closed  up  again  and  before  the  measurement  is  proceeded 
with,  the  refractometer  is  left  standing  for  a  few  minutes 
in  order  to  compensate  any  cooling  or  heating  of  the  prisms 
which  may  have  occurred  while  they  were  separated. 

The  fitting  for  heating  the  prisms  of  the  refractometer 


INSTRUMENTS  USED  IN  SUGAR  LABORATORIES    9 

is  constructed  in  its  essential  parts  on  Dr.  R.  Wollny's 
plan  by  enclosing  the  prisms  in  a 'metal  casing  with  double 
walls,  through  which  water  of  a  given  temperature  is  cir- 
culated. The  thermometer  provided  registers  the  temper- 
ature of  the  water  circulating  through  the  prism-casing  at 
its  point  of  exit.  Attainment  of  a  constant  temperature  in 
the  current  of  water  is  necessary. 


TESTING  THE  ADJUSTMENT  OF  THE  REFRACTOMETER 

Each  refractometer  is  supplied  with  a  testing  plate 
made  of  glass  of  known  refractive  index,  the  value  of  which 
is  marked  on  the  upper  ground  surface  of  the  plate.  The 
plate  has  two  plane  polished  surfaces  which  form  a  sharp 
edge.  For  the  purpose  of  testing  the  refractometer  the 
refractive  index  of  the  plate  P  is  very  accurately  measured 
by  applying  it  several  times  in  succession,  the  prism  sur- 
face being  wiped  clean  after  each  measurement.  The  mean 
of  the  several  measurements  is  compared  with  the  value 
stated  on  the  plate,  and  if  agreement  is  found  in  the  fourth 
decimal,  the  adjustment  of  the  refractometer  may  be  con- 
sidered satisfactory. 

Should  the  mean  of  several  such  measurments  show  a 
concordant  deviation  of  several  units  in  the  fourth  decimal, 
the  refractometer  should  be  adjusted  in  the  following 
manner. 

The  testing  plate  is  placed  in  position,  and  the  index 
is  set  exactly  at  the  value  nD  engraved  in  the  plate.  The 
key  is  then  slipped  over  the  small  square  bar  situate  on 
the  front  side  of  the  telescopic-tube  and  turned  until  the 
borderline  exactly  crosses  the  point  of  intersection  of  the 
hair-lines.  Finally,  the  new  adjustment  thus  secured  is 
verified  in  the  usual  way  by  finding  the  borderline  and 
taking  the  readings. 

In  using  the  refractometer  for  sugar  solutions  it  must 
be  borne  in  mind  that  its  values  really  represent  rather  a 


10 


SUGAK  ANALYSIS 


determination  of  the  total  substances  in  solution,  that 
is  to  say,  the  total  soluble  solids,  and  that  100  minus  these 
total  solids  is  water.  In  other  words,  index  of  refraction 
values  are  essentially  of  the  same  order  as  specific  gravity 
values',  and  are  subject  to  the  same  limitations.  The 
purer  a  sugar  solution  is,  of  course,  the  closer  is  the  approach 
of  the  refractive  index  values  to  the  true  sucrose  content  of 
the  solution. 

The  refractive  index  of  sugar  solutions  of  different 
concentrations,  at  the  temperature  of  17.5°  C.,  was  pub- 
lished by  Stolle  in  1901.* 

In  1906  Tolman,  and  Smith  worked  out  such  a  table 
for  sugar  solutions  at  20°  C.f  This  follows: 


% 

Sucrose. 

Index  of 
Refraction 
20°  C. 

% 

Sucrose. 

Index  of 
Refraction 
20°  C. 

% 

Sucrose. 

Index  of 
Refraction 
20°  C. 

% 

Sucrose. 

Index  of 
Refraction 
20°  C. 

1 

1.3343 

24 

1.3705 

47 

1.4137 

70 

1.4653 

2 

1.3357 

25 

1.3722 

48 

1.4158 

71 

1.4677 

3 

1.3372 

26 

1.3739 

49 

1.4179 

72 

1.4701 

4 

1.3387 

27 

1.3756 

50 

1.4200 

73 

1.4726 

5 

1.3402 

28 

1.3774 

51 

1.4221 

74 

1.4751 

6 

1.3417 

29 

1.3792 

52 

1.4242 

75 

1.4776 

7 

1.3432 

30 

1.3810 

53 

1.4263 

76 

1.4801 

8 

1.3447 

31 

1.3828 

54 

1.4284 

77 

1.4826 

9 

1.3462 

32 

1.3847 

55 

1.4306 

78 

1.4851 

10 

1.3477 

33 

1.3865 

56 

1.4328 

79 

1.4877 

11 

1.3492 

34 

1  .  3883 

57 

1.4351 

80 

1.4903 

12 

1.3508 

35 

1.3902 

58 

1.4373 

81 

1.4929 

13 

1.3524 

36 

1.3921 

59 

1.4396 

82 

1.4955 

14 

1.3539 

37 

1.3940 

60 

1.4419 

83 

1.4981 

15 

1.3555 

38 

1.3959 

61 

1.4442 

84 

1.5007 

16 

1.3572 

39 

1.3978 

62 

1.4465 

85 

1.5034 

17 

1.3588 

40 

1.3997 

63 

1.4488 

86 

1.5061 

18 

1.3604 

41 

1.4017 

64 

1.4511 

87 

1.5088 

19 

1.3621 

42 

1.4036 

65 

1.4534 

88 

1.5115 

20 

1.3837 

43 

1.4056 

66 

1.4557 

89 

1.5142 

21 

1.3654 

44 

1.4076 

67 

1.4581 

90 

1.5170 

22 

1.3671 

45 

1.4096 

68 

1.4605 

23 

1.3688 

46 

1.4117 

69 

1.4629 

*  Zeitschrift  d.  V.R.Z.  Ind.,  Vol.  LI,  pp.  335  and  469. 
t  Journal  Am.  Chem.  Soc.,  1906,  p.  1480. 


INSTRUMENTS  USED  IN  SUGAR  LABORATORIES     11 


By  aid  of  the  following  table  corrections  may  be  made 
for  observations  taken  at  temperatures  other  than  20°  C. 
The  reading  of  the  index  of  refraction  is  made  at  room- 
temperature  and  this  reading  is  calculated  to  per  cent 
sucrose,  then  the  proper  correction  from  the  table  is  deter- 
mined and  applied. 


Sucrose. 

Index  at 
20°  C. 

Index  at 
30°  C. 

Difference. 

Correction  for  10°  C. 

Sucrose. 

Sucrose  from 
Brix  Table. 

2.18 

1.3358 

1.3348 

0.0010 

0.66 

0.64 

7.43 

1.3438 

1.3428 

0.0010 

0.66 

0.67 

15.82 

1  .  3569 

1.3557 

0.0012 

0.70 

0.70 

51.71 

1.4236 

1.4219 

0.0017 

0.81 

0.79 

62.52 

1.4477 

1.4459 

0.0018 

0.78 

0.76 

A  refractive-index  table  of  sugar  solutions  at  28°  C., 
was  worked  out  by  Prinsen  Geerligs  and  Van  West  in  1907,* 
and  this  table  gives  values  which  are  practically  identical 
with  those  obtainable  from  Tolman  and  Smith's  table 
by  aid  of  the  temperature-correction  factors  above  given. 

Hugh  Main's  tablef  is  calculated  for  the  temperature 
cf  20°  C.  and  is  slightly  at  variance  with  the  values  given 
by  Tolman  and  Smith. 

Among  recent  experimental  contributions  on  the  refractive 
indices  of  sugar  solutions  are  those  made  by  Otto  Schoenrock 
and  by  V.  Stanek. 

Schoenrock's  values  {  show  a  close  agreement  with  those 
of  Main  previously  referred  to;  Schoenrock  also  furnishes 
a  table  of  temperature  corrections  for  temperatures  varying 
from  10°  to  30°  C.  and  for  water  contents  from  30%  to 
100%. 

*  Prinsen  Geerligs,  De  Fabricatie  van  Suiker,  etc.,  1911,  p.  11. 
f  International  Sugar  Journal,  1907,  p.  481. 

t  Zeitschrift  der  Deutschen  Zucker  Industrie,  1911,  pp.  421-425. 
International  Sugar  Journal,  1911,  Vol.  13,  p.  398. 


12  SUGAR  ANALYSIS 

Stanek's  work  *  deals  with  the  determination  of  water 
in  raw  sugars  by  the  immersion  refractometer  and  shows 
very  promising  results  are  to  be  obtained  with  this  type  of 
instrument. 

Balances  and  Weights.  For  weighing  out  samples  for 
polarization,  a  balance  capable  of  weighing  up  to  300 
grams  and  sensible  to  1  milligram  will  answer.  For  water 
and  ash  determinations  an  analytical  balance  should  be 
used;  this  should  be  sensible  to  0.1  of  a  milligram,  and  be 
capable  of  bearing  a  charge  up  to  200  grams. 

A  good  balance  should  give  the  same  result  in  successive 
weighings  of  the  same  body;  the  two  halves  of  th6  beam 
should  be  of  equal  length;  the  balance  should  be  sensible 
to  a  small  load,  and  should  work  quickly. 

It  is  an  easy  matter  to  determine  whether  a  balance 
possesses  these  properties.  Repeated  weighings  of  the 
same  load  will  quickly  establish  whether  the  balance  is 
consistent  with  itself;  this  depends  principally  on  the  true- 
ness  of  its  knife-edges. 

To  determine  whether  both  halve:  of  the  beam  are 
of  the  same  length,  the  two  pans  should  be  loaded  with 
equal  weights.  If  the  arms  are  of  unequal  length,  the 
pan  attached  to  the  longer  arm  wrill  descend. 

To  test  the  sensibility,  load  both  pans  with  the  maximum 
weight  which  they  are  intended  to  bear,  and  then  add  to 
one  of  the  pans  the  weight  to  the  extent  of  which  the  balance 
is  supposed  to  be  sensible.  The  addition  of  this  slight 
extra  weight  should  cause  the  pan  on  which  it  has  been 
placed  to  descend. 

The  weights  used,  both  the  regular  weights  for 
analytical  purposes,  and  the  so-called  sugar-weights, 
normal  and  half  normal,  should  be  verified  from  time  to 
time,  as  they  will,  in  daily  use,  unavoidably  suffer  some 
wear  and  tear. 

*  International  Sugar  Journal,  1911,  Vol.  13,  p.  90. 


INSTRUMENTS  USED  IN  SUGAR  LABORATORIES     13 


For  use  with  For  use  with 

metric  c.c.  flasks.  Mohr  c.c.  flasks. 


metric  c.c.  flasks.  Mohr  c.c.  flasks. 

Normal   sugar-weight         =26.000  grams.      26.048  grams. 
Half-normal  sugar- weight  =  13. 000  grams.      13.024  grams. 

Most  of  the  weights  are  so  made  that  the  glug  or  stopper 
unscrews  from  the  body  of  the  weight,  and  slight  deficiencies 
in  weight  can  readily  be  corrected  by  inserting  tin-foil  or 
small  shot  into  the  cavity  after  removing  the  plug.  Should 
the  weights  be  too  heavy,  a  little  filing  will  readily  remedy 
the  evil. 

Graduation  and  Calibration  of  Measuring  Apparatus. 
Detailed  instruction  for  the  calibration  of  volumetric  appa- 
ratus is  given  in  an  article  by  Morse  and  Blaloch,  Amer. 
Chem.  Journ.Vol.  XVI,  p.  479,  and  in:  "  The  Testing  of  Glass 
Volumetric  Apparatus,"  by  N.  S.  Osborne  and  B.  H.  Veazey, 
Reprint  No.  92  from  Bulletin  of  the  Bureau  of  Standards, 
Vol.  IV,  No.  4,  Washington,  D.  C.,  1908,  the  following  direc- 
tions will  however  suffice  for  practical  laboratory  needs. 

Graduation  of  Pipettes.  The  pipette  to  be  tested  for 
its  accuracy  is  filled  to  the  exact  mark  with  water  of  the 
temperature  at  which  the  pipette  has  been  graduated,  the 
water  is  then  run  into  a  tared  beaker,  which  of  course  must 
be  perfectly  clean  and  dry,  the  pipette  allowed  to  drain 
in  touch  with  the  beaker  and  the  beaker  with  its  contents 
weighed  at  once. 

Graduation  of  Burettes.  The  burette  is  placed  in  an 
upright  position,  filled  with  water  of  the  temperature  at 
which  the  burette  was  graduated  and  successive  quantities, 
2,  5  or  10  c.c.  at  a  time  are  then  run  into  a  clean  and  per- 
fectly dry  beaker  and  quickly  weighed. 

Graduation  of  Flasks.  Sugar  flasks  are  graduated  either 
in  metric  cubic  centimeters,  or  in  Mohr  cubic  centimeters. 

A  metric  cubic  centimeter  is  the  space  occupied  by  the 
mass  of  1.000  gram  of  water  weighed  in  vacuo  at  the  tempera- 
ture 4°  C.,  the  temperature  of  maximum  density  of  water. 

At  20°  C.  the  metric  (true)  cubic   centimeter  is  equiv- 


14 


SUGAR  ANALYSIS 


alent  to  the  volume  occupied  by  0.998234  gram  of  water 
weighed  in  vacuo,  or  0.997174  gram  of  water  weighed  in 
air  with  brass  weights. 

The  International  Commission  has  officially  adopted 
the  metric  cubic  centimeter  as  the  standard  unit  of  volume 
for  sugar  flasks.  A  100  metric  c.c.  flask  at  20°  C.  must 
contain  99.7174  grams  of  distilled  water  weighed  in  air  with 
brass  weights. 

A  Mohr  cubic  centimeter  is  the  space  occupied  by  the 
mass  of  1.000  gram  of  distilled  water  at  the  temperature 
of  17.5°  C.  weighed  in  air  with  brass  weights. 

Sugar  flasks  are  graduated  in  Mohr  c.c.  by  weighing 
into  the  dry  flask,  in  air  with  brass  weights,  exactly  100 
grams  of  distilled  water  having  the  temperature  of  17.5°  C. 

To  ascertain  the  weight  of  water  which  at  1°  C.  shall 
be  of  the  same  volume,  i.e.  100  c.c.,  as  100  grams  of  water 
at  17.5°  C.,  use  the  formula: 


100  X 


density  of  water  at  t°  C. 
density  of  water  at  17.5°  C.' 


In  order  to  be  able  to  graduate  or  to  verify  graduated 
Mohr  flasks  at  temperatures  other  than  17.5°  C.,  the  follow- 
ing convenient  table  of  the  weight  of  water  of  different 


Temperature. 
Degrees  C. 

Weight  of  50  c.c. 
after  Mohr. 
17.5°  =1. 

Weight  of  100  c.c. 
after  Mohr. 
17.5°  =1. 

25.0 

49.916 

99.833 

25.5 

49.910 

99.820 

26.0 

49.903 

99.807 

26.5 

49.896 

99.793 

27.0 

49  .  890 

99.780 

27.5 

49.883 

99.767 

28.0 

49.877 

99.754 

28.5 

49.870 

99.740 

29.0 

49.863 

99.727 

29.5 

49.857 

99.714 

30.0 

49.850 

99.701 

INSTRUMENTS  USED  IN  SUGAR  LABORATORIES     15 

temperatures,  also  weighed  in  air  with  brass  weights,  is 
given  by  Prinsen  Geerligs.* 

Hydrometers.  The  hydrometers  used  in  the  analysis 
of  saccharine  solutions  embrace  specific-gravity  hydrome- 
ters and  instruments  graduated  according  to  an  arbitrary 
scale.  To  the  latter  belong  the  Baume  hydrometers,  and 
the  Brix  or  Balling  spindles.  The  degrees  of  a  Brix  hydrom- 
eter indicate  percentage  by  weight  of  sugar  when  immersed 
in  a  solution  of  pure  sugar. 

The  suggestion  has  been  made  to  replace  the  Baume 
scale  by  a  scale  graduated  in  so-called  densimetric  degrees. 
These  values  are  found  by  taking  the  specific  gravity 
corresponding  to  any  given  Baume  degree,  ignoring  the 
unit,  and  dividing  the  decimals  by  100 

Example. 


Baume 
Degrees. 

Densities. 

Densimetric 
Degrees. 

0 

1.0000 

0.00 

5 

1.0356 

3.56 

10 

1.0731 

7.31 

50 

1.5161 

51.61 

This  scale  has,  however,  not  been  adopted  in  general  prac- 
tice, although  it  affords  an  advantage  over  the  Baume  scale 
for  purposes  of  calculation.  Wherever  it  can  be  done  in 
sugar  work  Brix  hydrometers  should  be  used  in  preference 
to  Baume  instruments. 

The  range  of  scale  in  each  and  all  of  these  hydrome- 
ters of  course  varies  greatly,  according  to  the  ideas  and 
preference  of  the  makers,  and  of  those  who  use  the  instru- 
ments. The  following  will  be  found  to  be  convenient 


*  Methods  of  Chemical  Control  in  Cane  Sugar  Factories.     Altrin- 
cham,  1905. 


16  SUGAE  ANALYSIS 

graduations  for  the  ordinary  requirements  of  the  house 
and  laboratory: 

Specific-gravity  Scale.  Range  from  1.095  to  1.106. 
The  scale  bears  twelve  full  divisions,  and  these  are  divided 
into  halves. 

The  Brix  Hydrometers.  Range  from  0°  to  28°,  spread 
over  three  instruments:  the  first  from  0°  to  8°,  the  second 
from  8°  to  16°,  the  third  from  16°  to  28°.  Each  degree 
is  divided  into  tenths. 

The  Baume  Hydrometers  for  Liquids  heavier  than  Water. 
For  general  use  in  the  refinery,  a  scale  on  a  single  instru- 
ment ranging  from  0°  to  50°,  and  divided  into  quarters 
or  halves,  will  prove  sufficient.  For  work  at  the  "  blow- 
ups "  the  range  of  scale  is  from  27°  to  32°,  and  each  degree 
is  divided  into  tenths.  For  the  syrup-boiler  a  scale  from 
32°  or  from  38°  to  44°,  also  divided  into  tenths,  is  desirable. 
For  laboratory  work  the  range  is  from  0°  to  45°,  best  carried 
over  three  or  more  instruments:  for  instance,  from  0°  to 
20°,  from  20°  to  35°,  and  from  35°  to  45°;  the  subdivision 
to  be  in  tenths  of  a  degree. 

It  is  a  matter  of  great  importance  that  the  hydrometers 
used  in  analytical  work  be  correct.  Every  instrument 
should  be  examined  in  at  least  three  places,  these  being 
preferably  chosen  at  points  corresponding  to  the  upper, 
the  middle,  and  the  lower  part  of  the  scale. 

If  a  correct  instrument  is  at  hand  (ascertained  to  be 
correct  by  careful  examination),  other  hydrometers  of 
the  same  scale  are  readily  tested  by  comparison  with  the 
standard  hydrometer.  If  a  standard  is  not  available, 
the  testing  must  be  done  in  comparison  with  very  accurate 
specific-gravity  determinations,  made  by  a  balance.  If 
the  instrument  tested  is  a  specific-gravity  hydrometer, 
the  balance  determinations  are  of  course  directly  compared 
with  its  readings;  if  it  is  a  Brix  or  a  Baume  spindle,  the 
corresponding  specific-gravity  values  can  be  ascertained 
from  Table  I. 


INSTRUMENTS  USED  IN  SUGAR  LABORATORIES     17 

Methods  of  Testing  Hydrometers.  Method  I.  The  bal- 
ance determinations  are  made  by  weighing  first  a  specific- 
gravity  flask  or  pycnometer,*  perfectly  clean  and  dry. 
The  flask  is  then  filled  with  distilled  water  at  the  tem- 
perature at  which  the  hydrometer  was  graduated.  This 
is  usually  17.5°  C.  or  20.0°  C.;  the  weight  of  the  flask 
filled  with  water  up  to  the  mark  is  next  taken.  A  solu- 
tion is  then  prepared  by  dissolving  pure  sugar  in  water. 
The  density  of  this  solution  is  such  that  it  corresponds 
approximately  to  one  of  the  points  marked  on  the  scale 
of  the  hydrometer  which  is  being  tested.  The  tem- 
perature of  the  solution  is  made  to  correspond  exactly 
with  the  temperature  at  which  the  specific-gravity  flask 
was  previously  filled,  and  the  weight  of  this  flask,  now  filled 
with  the  sugar  solution,  is  accurately  determined. 

Subtracting  the  weight  of  the  flask  from  these  two 
weighings  gives  respectively  the  weight  of  equal  volumes 
of  water  and  of  sugar  solution.  Dividing  the  latter  value 
by  the  former,  gives  the  specific  gravity  of  the  sugar  solution. 

Example. 

Weight  of  specific-gravity  flask + water,  40.0403 

15.0811 


Weight  of  water  in  flask,  24 . 9592 


Weight  of  specific-gravity  flask+sugar  solution,        42.5810 
"  "  "  15.0811 


Weight  of  sugar  solution  in  flask,  27 . 4999 


27. 4999 -=-24. 9592  =  1.1018 
Specific  gravity  of  sugar  solution  =  1.1018 

*  The  neck  where  the  mark  is  placed,  should  be  narrow,  and  the 
flask  should  have  a  tightly-fitting  stopper  to  prevent  loss  by  evapo- 
ration. 


18 


SUGAR  ANALYSIS 


Some  of  the  sugar  solution  is  poured  into  a  glass  cylin- 
der, the  temperature  carefully  brought  to  the  temperature 
at  which  the  hydrometer  was  graduated,  and  the  hydrom- 
eter, perfectly  clean  and  dry,  inserted.  It  should  be 
allowed  to  glide  down  slowly  into  the  solution  in  order 
that  no  more  of  the  stem  shall  be  immersed  than  is  neces- 
sary. Care  must  also  be  taken  that  the  instrument  floats 
free,  that  is,  does  not  come  in  contact  with  the  sides. 

When  the  hydrometer  has  come  to  rest,  a  reading  of 
the  scale  is  made  and  compared  with  the  specific  gravity 
obtained  by  the  balance. 

The  indications  of  specific-gravity  hydrometers  should 
of  course  agree  exactly  with  the  balance  determinations; 
for  Brix  and  for  Baume  instruments  the  limit  of  agreement 
should  be  placed  at  ±  0.10°  and  the  necessary  correction 
should  be  made  when  using  them.  The  cheaper  Baume 
hydrometers,  ranging  from  0°  to  50°,  will,  however,  rarely 
agree  closer  than  ±  0.20°,  and  this  degree  of  accuracy  will 
suffice  for  practical  working  purposes. 

Method  II.  If  the  hydrometer  is  a  specific-gravity 
hydrometer  of  limited  range,  it  may  be  tested  by  immer- 
sion in  solutions  of  chemically  pure  sugar;  these  solutions 
are  prepared  as  follows: 


Sp.  Gravity. 

Grams  C.  P. 
Sugar. 

Grams  Distilled 
Water  at  17°.  5  C. 

1.095 

22.6 

77.4 

1.097 

23.0 

77.0 

1.100 

23.7 

76.3 

1  .  103 

24.3 

75.7 

1.106 

25.0 

75.0 

Preparation  of  Pure  Sucrose.  The  method  recommended 
by  the  International  Commission  for  Uniform  Methods 
of  Sugar  Analysis,  is  as  follows: 

"  Purest  commercial  sugar  is  to  be  further  purified 
in  the  following  manner.  A  hot  saturated  aqueous  solu- 


INSTRUMENTS  USED  IN  SUGAR  LABORATORIES    19 

tion  is  prepared  and  the  sugar  precipitated  with  absolute 
ethyl  alcohol;  the  sugar  is  carefully  spun  in  a  small  centrif- 
ugal machine  and  washed  in  the  latter  with  some  alcohol. 
The  sugar  thus  obtained  is  redissolvcd  in  water,  again  the 
saturated  solution  is  precipitated  with  alcohol,  and  washed 
as  above.  The  product  of  the  second  centrifugaling  is 
dried  between  blotting  paper  and  preserved  in  glass  vessels 
for  use.  The  moisture  still  contained  in  the  sugar  is  deter- 
mined and  taken  into  account  when  weighing  the  sugar 
which  is  to  be  used." 

Method  III.  If  a  balance  is  not  available,  the  testing 
of  specific-gravity  hydrometers  may  be  accomplished 
by  the  aid  of  a  polariscope.  This  method  is  also  applicable 
to  Brix  and  to  Baume  hydrometers  if  their  degrees  are 
translated  into  the  corresponding  specific-gravity  values. 

A  solution  of  pure  sugar  is  made,  its  temperature  is 
taken,  and  the  hydrometer  inserted  in  it  with  all  the  care 
and  precautions  previously  referred  to.  After  the  reading  of 
the  hydrometer  has  been  noted,  the  solution  is  polarized, 
and  the  polarization  is  multiplied  by  the  factor  (Table  IV) 
corresponding  to  the  specific  gravity  of  the  solution,  cor- 
rected, if  necessary,  for  temperature  (Table  II).  If  the 
hydrometer  is  correct  (of  course  a  correct  polariscope  is 
premised),  the  result  of  the  multiplication  of  the  polariza- 
tion by  the  factor  must  be  100. 

Example. 
Specific  gravity  of   solution  corrected  for 

temperature, 1 . 096 

Factor, 1.042 

Polarization, 96.0 

96.0X1.042  =  100.0. 

Determination   of   the    Density   of   Solutions.    By   the 

Specific-gravity  Flask.  The  most  accurate  way  to  deter- 
mine the  density  (specific  gravity)  of  a  solution  is  by  means 
of  a  specific-gravity  flask  (pycnometer)  and  a  delicate 


20  SUGAB  ANALYSIS 

balance.  The  weight  of  the  flask,  empty  and  dry,  having 
been  ascertained,  and  the  weight  of  distilled  water  which 
it  will  hold  at  4°  C.,  or  at  the  temperature  at  which  it  was 
graduated,  being  known  once  for  all,  it  is  only  necessary 
to  fill  the  clean  and  dry  flask  exactly  up  to  the  mark  with 
the  solution  whose  specific  gravity  is  to  be  determined. 
If  the  solution  has  not  been  brought  to  the  temperature 
at  which  the  flask  was  graduated,  before  the  flask  is  filled 
with  it,  this  must  be  done  before  the  weighing  is  made, 
in  order  that  the  weight  of  equal  volumes  of  the  water 
and  of  the  solution  may  be  obtained. 

The  flask  filled  with  the  solution  is  weighed,  the  weight 
of  the  flask  subtracted  from  this  figure,  and  the  remainder 
divided  by  the  weight  of  the  corresponding  volume  of  water. 
The  result  is  the  specific  gravity  of  the  solution. 

The  Briihl  flask  especially  intended  for  making  specific- 
gravity  determinations  of  viscous  liquids  is  provided  with 
a  glass  tube  inserted  at  right  angles  to  the  neck  of  the  pyc- 
nometer,  somewhat  above  the  mark.  This  tube,  as  well  as 
the  regular  mouth  of  the  flask,  is  closed  by  a  glass  stopper. 
The  diameter  of  the  neck  should  not  be  less  than  2  c.m. 

To  fill  the  pycnometer  the  liquid  is  drawn  into  a  pipette 
and  the  latter  inserted  in  a  rubber  stopper  placed  in  the 
,  neck  of  the  flask.  An  aspirator  is  attached  to  the  side- 
tube  and  the  contents  of  the  pipette  are  drawn  into  the 
flask  by  suction. 

An  instrument  due  to  Scheibler  used  for  the  same  pur- 
pose consists  of  the  body  of  a  pipette  both  ends  of  which 
are  provided  with  glass  stop-cocks.  To  each  of  these  ends 
a  well  ground  detachable  glass  tube  is  fitted.  To  carry  out 
a  specific-gravity  determination  with  this  both  tubes  are 
attached,  the  stop-cocks  are  opened  and  the  lower  tube  is 
inserted  in  the  liquid  the  density  of  which  is  to  be  deter- 
mined. The  body  of  the  pipette  and  a  small  part  of  the 
upper  tube  are  filled  by  suction  with  the  liquid.  The 
lower  stop-cock  is  then  closed,  the  tube  attached  to  it 


INSTRUMENTS  USED  IN  SUGAR  LABORATORIES    21 

removed  and  the  body  of  the  pipette  with  its  contents  is 
immersed  in  water  of  the  standard  temperature  until  the 
desired  temperature  has  been  attained.  The  upper  stop- 
cock is  then  closed,  the  remaining  tube  is  detached  and  the 
apparatus  dried  and  weighed.  The  weight  of  an  equal 
volume  of  water  of  the  standard  temperature  having  been 
determined  once  for  all,  the  weight  of  pipette  plus  liquid, 
divided  by  the  weight  of  pipette  plus  water,  gives  at  once 
the  specific  gravity  of  the  liquid. 

By  Pipette  and  Beaker.  An  adaptation  of  the  methods 
just  described,  and  which  is  convenient  for  rapid  working 
is  the  following: 

A  pipette  capable  of  holding  a  certain  volume,  say 
10  or  20  c.c.,  is  placed  in  a  glass  beaker;  both  pipette  and 
beaker  of  course  must  be  perfectly  clean  and  dry.  The 
combined  weight  of  the  two  is  taken  and  noted. 

The  pipette  is  then  filled  with  distilled  water  at  the 
temperature  selected  as  the  normal  temperature.  The 
pipette  is  replaced  in  the  beaker,  and  the  combined  weight 
of  the  pipette,  beaker,  and  water  is  determined.  The 
vessels  having  been  again  cleaned  and  dried,  the  solution 
whose  specific  gravity  is  to  be  determined,  is  brought  to 
the  standard  temperature,  and  the  pipette  filled  with  it 
up  to  the  mark.  The  weight  of  pipette,  beaker,  and  solu- 
tion is  then  determined.  The  calculation  to  be  made  is 
exactly  as  before  explained,  the  combined  weight  of  beaker 
and  pipette  taking  the  place  of  the  weight  of  the  pycnometer 
in  the  previous  method. 

By  Hydrometers.  The  hydrometer  selected  for  mak- 
ing the  determination  may  be  a  specific-gravity  hydrometer 
or  an  instrument  graduated  according  to  an  arbitrary  scale 
(Brix,  Baume). 

Whenever  a  solution  is  to  be  tested,  care  must  be  taken 
to  have  it  as  free  from  air-bubbles  as  possible.  If  the 
solution  whose  density  is  to  be  determined  is  a  thick  syrup  or 
a  molasses,  it  had  best  be  poured  into  a  vessel  provided 


22  SUGAR  ANALYSIS 

at  the  bottom  with  a  stop-cock.  This  vessel,  advantage- 
ously enclosed  in  a  water-jacket,  may  be  heated  and  the 
molasses  thus  readily  warmed;  this  will  greatly  hasten 
and  facilitate  the  rising  of  the  air  bubbles.  When  these 
have  all  risen  to  the  top,  the  liquid  is  drawn  off  from  below, 
without  disturbing  the  frothy  layer  on  the  surface. 

The  liquid  is  then  placed  into  a  glass  cylinder,  which 
must  stand  perfectly  level,  and  the  hydrometer  is  carefully 
and  slowly  inserted.  It  must  float  free  in  the  liquid,  that 
is,  it  must  not  be  permitted  to  touch  the  sides  of  the  cylinder. 
When  the  hydrometer  has  come  to  rest,  the  point  up  to 
which  it  is  immersed  in  the  solution  is  read  and  recorded. 
The  temperature  of  the  solution  is  determined,  and  if  not 
of  the  standard  temperature,  a  correction  therefore  must 
be  made.  (See  Table  II  or  III.) 

The  readings  of  the  specific  gravity,  the  Brix,  and  the 
Baume  hydrometers  can  each  readily  be  translated  into 
the  terms  of  the  others  by  Table  I. 

By  Gravimeter.  A  convenient  instrument  devised  by 
W.  K.  Gird  permits  the  convenient  determination  of  the 
specific  gravity  of  saccharine  solutions  and  at  the  same  time 
measures  out  the  exact  amount  by  weight  of  such  solutions 
for  analysis. 

To  quote  Gird,  this  instrument  consists  of  a  brass  tube 
standard  about  twelve  inches  high  and  one  and  one-half 
inches  in  diameter.  About  three  inches  from  the  top  a 
small  tube  makes  connection  with  the  large  one,  extends 
parallel  with  and  as  high  as  the  large  tube,  and  then  turning 
down  again,  forming  a  siphon.  The  idea  of  having  the 
connection  made  below  the  top  of  the  large  tube  is  to  allow 
clear  fluid  free  from  bubbles  or  froth  to  run  out. 

The  large  tube  is  filled  with  juice  direct  from  the  beet, 
until  it  runs  out  of  the  small  tube,  when  it  is  allowed  to 
settle,  exactlj-  level  with  the  top  of  the  siphon.  The  sac- 
charometer,  weighing  26.048  grams,  is  then  inserted  in  the 
large  tube,  and  settles  down  until  it  has  displaced  through 


INSTRUMENTS  USED  IN  SUGAR  LABORATORIES    23 

the  siphon  exactly  its  own  weight — 26.048  grams — of  the 
juice.  This  is  the  exact  weight  of  juice  required  and  is 
ready  for  the  filter  and  polariscope. 

By  Araeo-pycnometers.  Araeometers  of  a  somewhat 
modified  form  have  been  devised  by  Fritsch  and  Eichhorn. 
They  offer  the  important  advantage  of  requiring  but  a 
small  amount  of  solution  for  specific-gravity  determinations. 
These  instruments  are  shaped  like  araeometers  excepting 
that  between  the  usual  float  and  the  mercury  bulb  another 
bulb  is  placed  which  is  provided  with  a  tight  fitting  glass 
stopper.  This  bulb  is  completely  filled  with  the  liquid  to 
be  tested,  the  stopper  inserted  and  the  instrument  is  then 
floated  in  a  cylinder  which  contains  water  of  the  standard 
temperature.  A  reading  of  the  scale  in  the  stem  of  the 
araeo-pycnometer  shows  at  once  the  specific  gravity  of  the 
solution  tested. 

By  Glass  Spheres.  For  approximate  density  determina- 
tion small  glass  bulbs  of  different  weights  are  sometimes 
used;  a  number  engraved  or  etched  on  each,  designates  the 
density  of  a  liquid  in  which  it  will  float. 

Beginning  with  the  heavier,  these  bulbs  are  successively 
thrown  into  the  solution  whose  density  is  to  be  determined, 
until  one  is  found  whrch  will  float  in  the  liquid  tested. 
The  number  engraved  on  this  bulb  indicates  the  density 
of  the  solution.  Of  course  regard  must  here  also  be  had 
to  the  temperature  of  the  liquid. 

By  Mohr's  Hydrostatic  Balance.  From  one  end  of  the 
beam  of  this  balance  a  glass  bob,  preferably  one  provided 
with  an  accurate  thermometer,  is  suspended  by  a  fine  plat- 
inum wire*.  The  other  end  of  the  beam  is  provided  with 
a  counterpoise  to  the  bob;  this  counterpoise  terminates 
in  a  fine  metal  point,  and  serves  as  the  tongue  of  the  balance. 
It  shows  the  beam  to  be  in  equilibrium  when  the  same 

*  The  Reimann  thermometer-bob  displaces  exactly  5  c.c.  of  dis- 
tilled water;  its  weight  is  less  than  15.0  grams  to  which  weight  the 
total  weight  is  readily  brought  by  a  metal  sinker. 


24  SUGAR  ANALYSIS 

remains  at  rest  in  a  horizontal  position  directly  opposite 
to  a  fixed  metal  point. 

The  balance,  when  correctly  adjusted,  is  in  perfect 
equilibrium  when  the  glass  bob  hangs  freely  suspended  in 
air. 

That  part  of  the  beam  between  the  fulcrum  and  the 
end  from  which  the  bob  is  pendant,  is  provided  with  nine 
graduations,  numbered  from  one  to  nine.  Accompanying 
the  balance  are  five  weights  or  riders.  The  largest  two 
are  each  equal  to  that  weight  of  distilled  water  at  a  given 
temperature,  which  the  glass  bob  displaces  when  it  is  im- 
mersed. The  other  three  riders  weigh  respectively  one 
tenth,  one  hundredth,  and  one  thousandth  as  much  as  the 
large  rider. 

When  the  bob  is  immersed  in  water,  one  of  the  large 
riders  must  be  placed  at  that  end  of  the  beam  from  which 
the  bob  is  suspended.  This  will  restore  the  equilibrium, 
and  the  balance  then  indicates  the  specific  gravity  1.000. 

If  the  bob  is  immersed  in  a  liquid  heavier  than  water, 
this  liquid  having  been  brought  to  the  temperature  for 
which  the  balance  was  graduated,  some  of  the  other  riders 
also  must  be  placed  on  the  beam  in  order  to  restore  the 
equilibrium.  The  position  of  these  riders  indicates  the 
specific  gravity  of  the  solution,  each  rider  according  to  its 
weight,  representing  respectively  as  many  tenths,  hundredths, 
or  thousandths  as  is  expressed  by  the  numbered  division 
on  the  beam  where  it  is  placed. 

By  Analytical  Balance.  Specific-gravity  determinations 
of  solutions  can  also  be  rapidly  and  easily  effected  in  the 
following  manner. 

Take  a  piece  of  metal  or  glass  of  convenient  form. 
Determine  its  weight  in  air  and  its  weight  in  water.  From 
these  data  calculate  its  specific  gravity.  The  weight  of  the 
body  in  air  divided  by  its  specific  gravity  expresses  the  vol- 
ume of  the  body  and  of  course  represents  also  the  weight 
of  the  volume  of  water  which  this  body  displaces  on  immer- 


INSTRUMENTS  USED  IN  SUGAR  LABORATORIES    25 

sion,  presuming  the  metric  system  of  weights  and  meas- 
ure is  employed.  These  data  having  once  been  ascertained 
the  body  need  only  be  immersed  and  weighed  in  the  solu- 
tion the  specific  gravity  of  which  is  sought  and  the  result 
found  by  a  simple  calculation. 

Example. 

Weight  of  the  metal  in  air 12 . 000  grs. 

Specific  gravity  of  the  metal 2.4 

Weight  of  the  metal  in  the  sugar  solution 6 . 495  grs. 

12  0 

Volume  of  metal  =  -^-r  =  5.0. 
2.4 

That  is  to  say,  this  piece  of  metal  when  immersed  in  water 
will  displace  5.0  grams  of  water.  The  metal  when  immersed 
in  the  sugar  solution  displaces: 

12.000 
6.495 


5.505  grams  of  the  sugar  solution, 

hence  the  specific  gravity  of  the  sugar  solution  is  equal  to: 
5.505 


5.000 


=  1.101. 


Calculation  of  Weight  of  Solids  and  Liquids  from  their 
Specific  Gravity.  One  cubic  foot  of  distilled  water  weighs 
62.50  lbs.  =  1000  ounces.  The  specific  gravity  of  water  is 
1.000.  If  the  decimal  point  of  a  specific-gravity  value  be 
moved  three  places  to  the  right,  the  weight  of  a  cubic  foot 
in  ounces  will  be  obtained.  This  figure  divided  by  16  gives 
the  weight  of  a  cubic  foot  in  pounds.  From  this  the  fol- 
lowing rule  is  deduced: 

To  find  the  weight  in  pounds  per  cubic  foot: 

Determine  the  specific  gravity,  remove  the  decimal  point 
three  places  to  the  right,  and  divide  by  16. 


26  SUGAK  ANALYSIS 

Example.     Specific  gravity  of  a  substance  is  0.87904. 
879.04 -=-16  =  54.94 

Hence  this  substance  weighs  54.94  Ibs.  per  cubic  foot. 

As  above  stated,  if  the  decimal  point  of  a  specific- 
gravity  value  is  removed  three  places  to  the  right,  the 
weight  of  a  cubic  foot  in  ounces  will  be  obtained,  and  this 
figure  divided  by  16  will  give  the  weight  of  a  cubic  foot 
in  pounds.  But  if  the  cubic  foot  be  assumed  equal  to  7.5 
gallons,  7.5  X 16  =  120.  Therefore, 

To  find  the  weight  of  a  gallon  in  pounds: 

Determine  the  specific  gravity,  remove  the  decimal  point 
three  places  to  the  right,  and  divide  by  120. 

Example.     A    syrup    has   a    specific    gravity   of    1.413. 

1413 -=-120  =  11. 78, 

hence  the  syrup  weighs  11.78  Ibs.  per  gallon. 

Colorimeters.  The  color-tests  made  on  sugars  and  on 
sugar  solutions  are  generally  only  comparative,  that  is  to 
say,  the  color  of  the  sample  examined  is  compared  with 
that  of  some  other  sample  which  is  taken  as  the  standard. 

In  examining  the  color  of  sugar  solutions,  to  learn, 
for  instance,  how  effectively  a  certain  sugar  has  been  de- 
colorized in  passing  through  bone-black,  two  test-tubes, 
beakers,  or  cylinders  made  of  white  glass,  are  filled  to  an 
equal  height  with,  respectively,  the  sample  under  exami- 
nation and  the  "  standard  "  solution  with  which  the  sam- 
ple is  to  be  compared,  both  solutions  of  course  being  of 
equal  density. 

Various  forms  of  apparatus  have  been  designed  for 
effecting  comparison  of  color. 

The  colorimeters  of  Duboscq,  Stammer  and  C.  H. 
Wolff  are  very  similar  in  their  construction.  Duboscq's 
and  Wolff's  apparatus  require  standard  solutions  for  com- 


INSTRUMENTS  USED  IN  SUGAR' LABORATORIES    27 

parison  whereas  in  the  colorimeter  of  Stammer,  and  also 
in  the  "  tintometer  "  of  Lovibond,  the  standard  solution  is 
replaced  by  colored  glass  discs  of  various  tints,  by  the  com- 
bination of  which  it  is  possible  to  produce  almost  any 
shade  desired. 

As  the  depth  of  color  of  a  solution  is  proportional  to  the 
length  of  a  column  of  such  solution,  there  must  be  ascer- 
tained in  instruments  of  the  Stammer  type  the  height  of  a 
column  of  the  solution  which  will  in  color  correspond  to 
the  tint  of  some  "  standard  "  colored  glass  disc  or  discs 
inserted  in  an  adjoining  tube.  The  scale  is  graduated  in 
millimeters.  If,  for  instance,  a  depth  of  one  millimeter  of 
the  solution  corresponds  to  the  normal  tint,  the  color  is 
said  to  be  100.  If  two  millimeters  depth  of  solution  are 
required  to  match  the  tint,  the  color  is  50;  if  four  millimeters, 
25,  and  so  on. 

Thermometers.  All  thermometers  should  be,  if  pos- 
sible, compared  with  some  standard  instrument.  This 
applies  especially  to  the  thermometer  which  is  to  be  used 
to  determine  the  temperature  while  ascertaining  the  polariza- 
tion of  inverted  sugar  solutions.  It  will  answer  to  verify, 
on  Centigrade  thermometers  intended  for  ordinary  use, 
the  zero  and  the  100  mark;  on  a  Fahrenheit  instrument, 
the  32°  and  the  212°  mark,  and  in  both  of  course  to  see 
that  the  degrees  are  of  equal  size. 

The  zero  mark  on  the  Centigrade  scale  (32°  Fahrenheit) 
is  ascertained  by  placing  the  bulb  and  part  of  the  stem 
in  snow  or  pounded  ice  for  about  a  quarter  of  an  hour. 
The  vessel  in  which  the  snow  or  ice  is  placed  should  be 
provided  with  a  small  opening  at  the  bottom,  through  which 
the  water  is  drained  off  as  it  is  formed. 

To  obtain  the  100°  C.  (212°  F.)  mark,  the  thermometer 
is  suspended  in  the  vapor  of  boiling  water,  care  being  taken 
that  it  does  not  dip  into  the  water.  The  pressure  of  the 
atmosphere  should  be  760  m.m.  at  the  time;  if  not,  a  cor- 
rection for  the  variation  must  be  made. 


28  SUGAR  ANALYSIS 

The  reading  of  one  scale  can  be  translated  into  that 
of  the  other  by  the  following  formulae: 

To  change  °  C.  into  °  F.  ^- 


To  change  °  F.  into  °  C.  (°  F-~32)j  =  o  Q> 

y 

See  Table  XIX  for  a  comparison  of  different  thermometric 
scales. 


CHAPTER  III 
POLARISCOPES  AND  ACCESSORIES 

Polarization.  If  a  ray  of  light  strikes  a  glass  mirror 
and  makes  an  angle  of  about  55°  with  the  normal  of  the 
mirror,  the  ray  is  not  only  reflected,  but  is  endowed  with 
certain  properties,  and  is  said  to  be  polarized. 

In  Fig.  2,  ab  is  the  incident  ray,  be  the  polarized  ray. 
A  plane  conceived  as  passed  through  abc  is  called  the  plane 
of  polarization. 

If  a  polarized  ray  is  allowed  to  fall  upon  a  second  mirror, 
parallel  to  the  first,  it  is  again  reflected  at  the  angle  above 
mentioned.  If  this  second  mirror  is  turned 
around  be,  its  inclination  to  the  horizontal 
being  preserved  unchanged,  the  intensity 
of  the  reflected  ray  continuously  diminishes 
until,  when  the  rotation  has  been  carried 
through  90°,  the  light  is  extinguished  com- 
pletely. If  the  rotation  be  carried  beyond 
this  point  the  mirror  becomes  again 
illumined;  and  when  it  has  been  turned  FIG.  2. 

through  180°,  the  reflection  is  again  at 
its  maximum  of  brightness.  In  other  words,  the  intensity 
of  the  reflected  light  is  greatest  when  the  incident  ray 
and  the  polarized  ray,  after  reflection  from  the  second 
mirror,  are  in  the  same  plane,  and  least  when  these  rays 
are  in  planes  at  right  angles  to  each  other. 

Polarization  of  light  can  also  be  produced  by  other 
means:  by  repeated  single  refractions,  or  by  double  refrac- 
tion in  certain  crystals — Iceland-spar,  for  instance. 

29 


30  SUGAR  ANALYSIS 

If  a  plate  of  quartz,  cut  at  right  angles  to  its  principal 
axis,  is  inserted  between  two  mirrors  placed  as  above  de- 
scribed, and  traversed  by  a  polarized  ray,  the  image  of 
the  quartz  will  appear  in  color  in  the  upper  mirror.  The 
color  of  the  image  changes  with  the  turning  of  the  mirror; 
the  order  in  which  the  colors  appear  is  the  same  as  found 
in  the  solar  spectrum:  red,  yellow,  green,  blue,  and  violet. 

This  phenomenon  is  termed  circular  polarization.  It 
depends  on  the  property  possessed  by  quartz  of  rotating 
to  a  different  degree  the  planes  of  polarization  of  the  various 
colored  rays  which  compose  white  light.  One  variety  of 
quartz  shows  these  colors  in  the  order  named  when  the 
mirror  is  turned  to  the  right ;  a  second  variety  of  the  mineral 
exhibits  the  colors  in  this  sequence  only  when  the  rotation 
of  the  mirror  is  to  the  left.  These  varieties  of  quartz  are 
respectively  termed  right-rotating  and  left-rotating,  or 
dextrogyrate  and  levogyrate. 

Among  other  bodies  which  share  with  quartz  the  prop- 
erty of  circular  polarization  are  the  sugars  when  in  solution. 
Some  of  the  sugars  are  dextro-rotatory:  for  instance, 
sucrose,  dextrose,  and  raffinose;  others  rotate  the  plane  of 
polarized  light  to  the  left,  as  levulose  and  sorbinose. 

The  extent  to  which  the  plane  of  polarized  light  is 
turned  by  quartz,  by  a  sugar  solution  or  any  other  optically 
active  substance,  depends  on  the  thickness  of  the  layer 
which  the  polarized  ray  has  to  traverse.  The  thicker  the 
plate  or  the  longer  the  column  of  solution,  the  greater  the 
rotation  of  the  ray.  Whereas  in  the  case  of  a  quartz  plate 
the  thickness  of  the  plate  is  the  only  factor  to  be  considered, 
in  sugar  solutions  the  concentration  of  the  solution,  i.e., 
the  amount  of  sugar  in  the  solution,  must  be  taken  into 
account. 

Specific  Rotation.  The  polarizing  power  of  sucrose, 
termed  its  specific  rotation  or  specific  rotatory  power,  is 
the  angular  rotation  given  to  the  plane  of  polarization  by  a 
column  1  dcm.  long  of  a  100%  solution  of  sucrose. 


POLARISCOPES  AND  ACCESSORIES  31 

This  angular  rotation  depends  upon  the  wave  length  of 
the  light  used  and  it  is  therefore  necessary  to  specify  this. 
It  is  customary  to  denote  the  angular  rotation  by  the  letter 
a,  and  the  specific  roation  by  the  term  [«]. 

Specific  rotation  of  the  mean  yellow  light  ray  is  designated 
by  the  expression  [a],,  that  of  the  bright  yellow  line  of  sodium 
by  [a]D.  In  addition  it  is  customary  to  indicate  also  the 
temperature  at  which  the  value  is  determined,  thus  if  this 

20 
be  20°  C.  the  symbol  becomes  [a]  — . 

Specific  rotation  is  calculated  by  the  formula 

100  X  a 


a  =• 


cxr 


in  which :  a  =  angular  rotation  of  the  solution, 
c  =  grams  per  100  c.c.  of  solution, 
/  =  length  in  decimeters  of  the  observation  tube. 

Or,  it  can  be  calculated  by  the  formula: 

lOOa 

M  =  ~ : 


in  which :  a  =  angular  rotation  of  the  solution, 

d  =  the  specific  gravity  of  the  solution, 

poparts  by  weight  of  the  sucrose  in  100  parts 

by  weight  of  the  solution, 
1  =  length  in  decimeters  of  the  observation  tube. 

In  this  expression  it  will  be  seen  that  pXd  corresponds  to 
the  c  of  the  previous  equation. 

The  specific  rotation  of  sucrose  is  +66.6.  This  can 
be  determined  by  obtaining  the  reading  of  a  sucrose  solu- 
tion of  known  concentration  in  a  polariscope,  changing 
this  value  to  angular  degrees  by  the  factor  1°  Ventzke 
=  0.34657  angular  degrees  and  applying  the  [a]D  formula. 


32  SUGAR  ANALYSIS 

If,  for  instance,  a  13%  by  weight  solution  of  sucrose  he 
prepared  and  polarized  at  20°  C.  in  a  2  dcm.  tube,  the  read- 
ing found  is  multiplied  by  0.34657  and  b^  100,  and  then 
divided  by  13X2.  Thus:  13  grams  of  sucrose  dissolved  at 
20°  C.  to  100  metric  cubic  centimeters  give,  in  a  2  dcm. 
tube,  a  reading  of  50°  Ventzke  on  the  polariscope. 

f  ,20     (50 X. 34657)  100 
[a]D=  13X2 

Conversion  factors.  * 

Normal  weight  for  Ventzke  scale  =  26.00  grams 
French  scale  =  16.29      '  * 
Wild  scale       =10.00      " 

1°  Ventzke  scale  =  0.34657°  angular  rotation  D. 
1°  French       "    =0.21666°       " 
l°Wild         ."     =0.13284°       " 

1°  Ventzke  scale  =  1.59960°  French  scale 
1°        "          "    =2.60903°  Wild  scale 

1°  French  scale    =0.62516°  Ventzke  scale 
1°        "         "      =1.63098°  Wild  scale 

1°  Wild  scale      =0.38329°  Ventzke  scale 
1°      "        "         =0.61313°  French  scale. 

Polariscopes — Saccharimeters.  Basing  on  the  property 
of  circular  polarization,  instruments  have  been  constructed 
by  which  the  strength  of  solutions  containing  optically  active 
substances  can  be  determined.  They  are  called  polariscopes 
or  polarimeters.  Polariscopes  intended  for  general  scien- 
tific work  are  provided  with  a  circular  disc,  graduated  in 
such  a  manner  that  the  angle  of  rotation  can  be  conveniently 
read.  Instruments  intended  for  some  special  purpose,  as 

*  C.  A.  Browne,  Handbook  of  Sugar  Analysis,  1912, 


POLARISCOPES  AND  ACCESSORIES  33 

for  instance,  for  sugar  analysis,  are  generally  provided 
with  a  scale  which,  if  certain  directions  have  been  followed 
in  the  preparation  of  the  solution,  will  at  once  indicate  in 
percentage  the  amount  of  the  optically  active  substance 
present.  Polariscopes  designed  especially  for  sugar  analysis 
are  termed  saccharimeters,  although  the  former  term  is 
also  often  employed  even  for  this  type  of  instrument. 

The  principle  on  which  these  instruments  are  con- 
structed is  briefly  this:  A  ray  of  light  is  polarized  by  pass- 
ing through  a  prism,  called  the  polarizer  and  generally 
made  of  Iceland-spar;  the  ray  is  then  made  to  traverse  a 
column  of  sugar  solution  of  known  length.  Emerging  from 
this,  it  passes  through  a  second  prism  of  Iceland-spar,  the 
analyzer,  which  corresponds  to  the  second  mirror  in  the 
apparatus  previously  described.  It  now  only  remains  to 
ascertain  the  extent  to.  which  the  plane  of  polarized  light 
has  been  rotated  by  the  sugar  solution.  The  arrangements 
by  which  this  is  effected  differ  in  the  various  forms  of 
saccharimeters,  but  in  the  more  modern  instruments  it  is 
generalljr  accomplished  by  allowing  the  light  on  its  emergence 
from  the  analyzer  to  pass  through  a  layer  of  quartz,  the 
thickness  of  which  (capable  of  accurate  measurement) 
can  be  so  regulated  as  to  compensate  exactly  the  rotation 
produced  by  the  sugar  solution.  It  is  assumed  that  the 
rotatory  dispersion  of  sugar  corresponds  to  that  of  quartz. 

The  field  of  vision  of  a  saccharimeter  is  either  one  of 
color,  or  else  exhibits,  when  correctly  set  at  zero,  a  uni- 
form faint  tint;  saccharimeters  showing  the  latter  are 
known  as  half-shade  or  half-shadow  instruments,  and  can 
be  used  by  color-blind  persons,  as  well  as  by  others. 

The  arrangement  of  the  optical  parts  of  saccharimeters 
is  shown  in  the  accompanying  Figs.  2  and  3.  Concerning 
the  adjustment  of  the  double- wedge  compensating  saccharim- 
eter, the  following  directions,  given  by  Schmidt  and  Haensch 
should  be  carefully  followed. 

Before  using  an  instrument  it  is  necessary  to  control 


34 


SUGAR  ANALYSIS 


the  zero  point.     After  the  red  scale  has  been  placed  on 
zero  the  wedge  corresponding  to  the  black  scale  is  moved 


i     2 


FIG.  3. — Soleil-Ventzke-Scheibler  Saccharimeter. 

1.  Magnifying-glass  for  reading  scale. 

2.  Telescope  for  observing  field  of  vision. 

3.  Nicol  prism,  analyzer. 

4.  Quartz-wedge,  fixed,  bearing  vernier.  "j 

5.  Quartz- wedge,. movable,  bearing  scale.  Rotation 

(Dextro-rotatory  if  4  and  5  are  levo-rotatory.    {Compensator. 

6.  Quartz  plate,  j  Levo.rotatory  if  4  and  5  are  dextro-rotatory.  J 

7.  Double  quartz  plate  (dextro-  and  levo-rotatory). 

8.  Nicol  prism,  polarizer. 

9.  Quartz  plate,  dextro-  or  levo-rotatory. 


10.  Nicol  prism. 


Regulator. 


10 


FIG.   4. — Double-wedge    Compensator    Saccharimeter,    Schmidt    and 
Haensch  Construction. 


1.  Eye-piece. 

2.  Objective. 

3.  Nicol  prism,  analyzer. 

i  Constituting   the 

4.  Quartz-wedge.         Double.wedge 


5.  Quartz-wedge. 


Compensator 


6.  Quartz-wedge.  J  Constituting    the 

Double-wedge 
I      Compensator. 


7.  Quartz-wedge. 

8.  Lens. 

9.  Nicol  prism. 

10.  Lens. 

11.  Lens. 


until  the   field   exhibits  the   same   tint   throughout.     The 
black  nonius  should  then  point  exactly  to  zero.     If  this  is 


POLARISCOPES  AND  ACCESSORIES  35 

not  the  case  the  wedge  is  moved  by  means  of  the  microm- 
eter-screw on  the  left  until  absolute  zero  is  obtained.  The 
correctness  of  this  zero  is  determined  by  repeated  trials. 
If  now,  after  both  scales  are  placed  at  zero,  one  side  of 
the  field  appears  colored  we  must  proceed  as  follows:  The 
wedges  are  removed  and  the  color  of  the  field  observed. 
The  large  wedges  are  removed  by  screwing  them  out  as  far 
as  they  will  go  and  then  simply  pulling  them  out;  then  the 
two  screws  are  removed  and  the  small  wedges  taken  out. 
If  now  the  field  does  not  show  an  even  tint  the  analyzer 
is  moved  by  the  two  screws  placed  at  the  side,  loosening  one 
and  tightening  the  other  correspondingly  until  the  desired 
result  is  reached.  The  small  wedges  are  now  put  back  in 
the  order  in  which  they  are  marked,  the  large  wedges  placed 
in  position,  and  the  zero  point  corrected  as  before.  The 
zero  point  of  the  instrument  is  now  accurate,  and  if  the 
divisions  of  the  scale  are  correct  the  quartz  plate  should  give 
the  correct  reading.  If,  however,  an  incorrect  reading  is 
obtained,  the  plate  should  be  taken  out  and  controlled  by 
means  of  the  red  scale.  If  this  gives  the  correct  reading 
the  black  scale  is  wrong,  otherwise  both  scales  are  inaccurate. 

The  U.  S.  Customs  Regulations  of  1907  prescribe  the 
double  quartz-wedge  compensation  saccharimeters  and  a 
polarizing  system  known  as  the  Lippich  half-shadow,  and 
state : 

"  Art.  58.  All  polariscopes  shall  be  so  adjusted  that 
when  a  200-millimeter  tube  filled  with  the  standard  sugar 
solution  is  polarized  at  20°  C.  the  instrument  shall  read 
100°  S  (sugar  degrees) ±0.01°  S  (sugar  degree).  All  points 
on  the  scale  shall  indicate  percentages  of  the  standard 
solution.  The  standard  sugar  solution  shall  be  prepared 
by  dissolving  26  grams  of  pure  sugar  in  pure  water  and 
making  up  the  volume  to  100  metric  cubic  centimeters,  all 
weighings  to  be  made  in  air  with  brass  weights  and  the  volume 
to  be  completed  at  20°  C.  A  length  of  200  millimeters  of 
the  standard  sugar  solution  shall  be  considered  to  give  a 


36  SUGAR  ANALYSIS 

rotation  of  40.728°  for  light  of  wave  length  5,461  centimeters 
X10~8." 

Bates'  Saccharimeter.  This  instrument  a  white  light 
polariscope  with  an  adjustable  sensibility  was  designed  by 
Frederick  J.  Bates  of  the  Bureau  of  Standards,  Washington, 
D.C. 

It  possesses  some  marked  advantages  over  the  several 
styles  of  half-shade  saccharimeters  in  more  general  use.* 
It  is  an  improved  quartz  compensating  instrument  the 
sensibility  of  which  can  be  instantly  adjusted  so  as  to 
afford  ample  light  for  the  observation  of  the  darkest  sugar 
solutions;  its  right  and  left  rotating  wedges  cover  a  wide 
range  from  —20°  sugar  to  +120°  sugar.  The  scale  is 
etched  on  ground  glass,  which  permits  of  very  sharp  rulings, 
and,  as  this  scale  is  illuminated  by  transmitted  instead  of 
by  reflected  light,  the  black  dividing  line  between  the 
vernier  and  the  scale  and  which  is  oftentimes  disturbing, 
is  done  away  with,  and  scale  readings  to  0.01°  sugar,  are 
made  possible. 

As  the  temperature  of  the  quartz-wedges  plays  so 
important  a  role  in  accurate  polarimetric  work,  a  thermom- 
eter with  a  horizontal  scale,  divided  into  one-fifth  degrees, 
is  mounted  on  the  metal  case  containing  the  compensator 
and  permits  accurate  ascertainment  of  the  temperature 
of  the  wedges. 

A  further  improvement  of  this  instrument  is  the  placing 
of  the  milled  heads,  which  move  the  quartz-wedges,  in  a 
position  at  right  angles  to  the  position  in  which  they  are 
usually  placed;  furthermore  these  wedges  can  be  instantly 
set  and  rigidly  fastened  at  any  position  of  the  scale. 

This  saccharimeter  is  equally  available  for  regular  com- 
mercial usage  and  for  the  most  refined  research  work  and 
certainly  marks  an  important  advance  in  the  evolution  of  this, 
the  most  important  instrument  used  in  the  sugar  industry. 

*See  American  Sugar  Industry,  Chicago,  Vol.  XIII,  No.  6,  1911, 
p.  254. 


POLARISCOPES  AND  ACCESSORIES  37 

Saccharimeter  Scales.  The  scales  of  saccharimeters 
are  constructed  by  ascertaining  the  number  of  degrees, 
minutes,  and  seconds  which  a  definite  amount  by  weight 
of  pure  sugar  dissolved  in  water  and  made  up  to  100  cubic 
centimeters  will  rotate  the  polarized  ray.  This  point  is 
marked  as  100,  and  the  scale  is  then  divided  into  one  hun- 
dred parts. 

If  the  same  weight  of  an  impure  sugar  is  brought  into 
solution  and  polarized  under  the  same  conditions,  the 
reading  in  the  polariscope  expresses  percentage  of  the  active 
substance  present. 

The  scales  of  different  saccharimeters  have  their  100 
mark  correspond  to  different  weights  of  pure  sugar.  In 
the  Laurent  and  in  the  Duboscq  instrument  it  is  16.192 
grams,  in  Wild's  it  is  10.000  grams,  and  in  the  Ventzke 
apparatus  26.048  grams  dissolved  to  100  Mohr  c.c.,  or  26.000 
grams  dissolved  to  100  metric  c.c.  These  values  are  termed 
the  "  normal  weights  "  of  the  respective  instruments.* 

The  100  mark  in  the  Ventzke  scale  was  originally  deter- 
mined f  by  preparing  from  pure  sugar  a  solution  having 
a  specific  gravity  of  1.100.  This  solution  placed  in  a  tube 
200  m.m.  in  length  deviated  the  plane  of  polarized  light 
to  a  certain  extent  and  this  point  was  marked  100°  on  the 
polariscope  scale.  Formerly,  in  order  to  test  a  sugar  sam- 
ple containing  less  than  100%  of  sugar,  there  was  pre- 
pared of  it  a  solution  having  the  above  specific  gravity; 
this  was  placed  in  a  200  m.m.  tube,  and  the  reading  on  the 
scale  of  the  polariscope  indicated  by  this  solution,  was 
regarded  as  giving  directly  the  percentage  by  weight  of 
sugar  in  the  dry  substance. 

This  method  of  procedure  was  however  soon  abandoned 
because  it  was  found  to  be  inexact,  as  the  salts  contained 

*  Confer:  Nasini  and  Villavecchia,  Sul  Peso  Normale  Pei  Sac- 
carimetri,  Roma,  1891. 

f  Landolt:  Zeitschrift  des  Vereines  fiir  Riibenzucker-Industrie, 
1891,  p.  515. 


38  SUGAR  ANALYSIS 

in  the  raw  sugars  also  influence  the  specific  gravity  of  the 
solution. 

It  was  ascertained  that  100  c.c.  of  Ventzke's  normal 
solution  contained  26.048  grams  of  pure  sucrose — hence 
if  this  weight  of  a  sugar  sample  is  dissolved  in  water  up  to 
100  c.c.  a  reading  of  such  a  solution  in  a  200  m.m.  tube 
will  indicate  directly  the  percentage  of  sugar. 

This  method  was  introduced  long  before  "  Mohr's  "  c.c. 
were  known.  The  26.048  grams  were  therefore  most  likely 
originally  intended  to  be  dissolved  up  to  100  metric  c.c. 
However  gradually  German  manufacturers  of  saccharim- 
eters  came  to  place  the  100  mark  on  their  instruments 
secured  by  means  of  solutions  containing  26.048  grams  of 
pure  sucrose  in  100  Mohr  c.c.  and  this  practice  was  quite 
generally  adopted  and  continued,  until  the  International 
Commission  for  Uniform  Methods  of  Sugar  Analysis,  in 
1900,  urged  the  adoption  of  the  metric  c.c.  for  sugar- work 
and  prescribed  26.000  grams  of  pure  sucrose  as  the  nor- 
mal weight  to  be  dissolved  up  to  100  metric  c.c.  at  20°  C., 
and  observed  in  a  tube  200  m.m.  long  at  20°  C.,  in  order  to 
secure  the  100°  mark  on  saccharimeters. 

In  order  to  adjust  a  saccharimeter,  first  obtain  by  the 
telescope  a  sharply  defined  view  of  the  field.  Then  turn 
the  screw  attached  to  the  quartz-wedge  until  both  halves 
of  the  field  are,  in  color  instruments,  of  the  same  tint;  or 
if  the  saccharimeter  is  a  half-shade  apparatus,  until  both 
halves  of  the  field  are  equally  illumined. 

When  this  has  been  done  the  position  of  the  scale  is 
carefully  read  through  the  magnifying-glass.  The  zero 
of  the  scale  should  be  exactly  in  line  with  the  zero  mark 
on  the  vernier;  if  this  is  not  the  case,  they  must  be  brought 
into  the  required  position  by  a  slight  turning  of  the  screw- 
micrometer  provided  for  the  purpose.  Care  must  be  taken 
that  the  screw  in  connection  with  the  analyzer  be  not  mis- 
taken for  the  other  screw,  or  the  whole  apparatus  will  be 
thrown  out  of  order. 


POLARISCOPES  AND  ACCESSORIES  39 

If  it  is  impossible  to  obtain  a  uniform  shade  or  tint 
on  both  sides  of  the  center  line  of  the  field,  the  polarizer 
and  the  analyzer  must  be  brought  into  adjustment. 

This  is  done  by  removing  the  movable  and  the  stationary 
quartz-wedges,  as  well  as  the  compensation  quartz  plate; 
the  cover  is  then  closed,  and  the  key  having  been  inserted 
in  the  screw-head  connected  with  the  analyzer  (this  screw- 
head  is  generally  placed  on  the  right-hand  side  of  the 
polariscope) ,  the  key  is  turned  untilthe  tint  in  both  halves 
of  the  field  is  uniform. 

The  wedges  and  the  plate  which  had  been  removed 
are  then  replaced,  and  the  zero  point  accurately 
adjusted. 

When  the  instrument  has  been  correctly  set  at  zero  a 
quartz  plate  of  known  value,  preferably  one  approximating 
the  average  test  of  the  sugar  solutions  to  be  examined,  is 
inserted  in  the  instrument,  and  the  correctness  of  that  part 
of  the  scale  ascertained. 

Adjustment  and  Examination  of  Saccharimeters.  In 
all  instruments  the  zero  point  should  be  determined  before 
every  observation;  where  press  of  work  renders  this  im- 
practicable, the  observation  should  be  insisted  on  at  least 
twice  daily — in  the  morning  before  a  polarization  is  made, 
and  again  in  the  middle  of  the  day.  If  the  zero  point  is 
out  a  few  tenths  only,  it  is  not  necessary  to  adjust  the  scale 
each  time  but  the  needed  correction  should  be  made  in 
noting  the  reading. 

When  a  solution  is  introduced  for  reading,  the  telescope 
must  first  be  properly  focussed,  as  before  stated,  to  insure 
a  clear  and  sharply  defined  view  of  the  field. 

If  the  scale  stood  at  zero  before  the  tube  filled  with 
the  solution  was  introduced,  a  glance  through  the  glass 
will  after  its  introduction  show  the  halves  of  the  field  to 
be  of  different  colors;  or,  if  a  half-shade  saccharimeter  is 
used,  one  half  of  the  field  will  appear  dark  and  the  other 
light. 


40 


SUGAR  ANALYSIS 


The  screw  attached  to  the  quartz-wedge  is  then  turned 
until  equality  in  tint  or  shade  shall  have  been  restored  to 
the  whole  field.  The  three  different  appearances  presented 
by  the  field  are  shown  in  the  following  diagram. 


FIG.  5. 

It  then  only  remains  to  read  the  scale.  Most 
instruments  have  the  degrees  divided  into  tenths.  First 
it  must  be  determined  how  many  whole  degrees  the  zero 
of  the  scale  is  removed  from  the  zero  of  the  vernier. 
When  this  has  been  ascertained,  attention  must  be  given 
to  the  tenths  of  a  degree  indicated.  The  number  of  divi- 
sions marking  tenths  on  the  vernier  are  counted  until  one 
is  found  which  coincides  perfectly  with  a  division  on  the 
movable  scale,  that  is  to  say,  which  appears  to  form  a 
continuation  of  that  line.  This  division  represents  the 
number  of  tenths  indicated.  The  accompanying  figure, 
for  instance,  shows  30.7°. 


rTTTn 


JO 


10 


Fin.  6. 


Most  saccharimeters  have  scales  possessing  a  range  from 
0°  to  100°.  Instruments  have  however  been  constructed, 
according  to  the  suggestions  of  Stammer  and  Strohmer,  the 
scales  of  which  have  a  range  of  only  from  80°  to  100°.  A 
polarization  tube  400  m.m.  in  length  is  usually  employed 


POLARISCOPES  AND  ACCESSORIES  41 

with  these  saccharimeters  and  readings  to  within  ±0.05° 
can  be  obtained. 

The  sources  of  error  in  saccharimeters  are  numerous 
and  therefore  every  instrument,  before  being  placed  in  use, 
should  be  carefully  examined. 

To  determine  whether  the  scale  is  correct,  adjust  the 
zero  point  exactly.  Make  100  c.c.  of  a  sugar  solution  by 
dissolving  the  normal  weight  of  chemically  pure  sugar 
in  water,  and  polarize.  This  solution  should  read  100 
degrees  (per  cent)  on  the  scale  if  the  instrument  is  correctly 
constructed.  If  it  does  not  read  100,  the  instrument  should 
be  rejected. 

The  need  of  constantly  controlling  the  adjustment  of 
saccharimeters  with  quartz  plates  or  sugar  solutions  of 
known  value,  has  already  been  referred  to. 

In  instruments  of  earlier  make,  provided  with  ivory 
scales,  the  scale  itself  was  frequently  a  cause  of  introducing 
error,  as  it  was  liable  to  distortion  by  variation  in  tem- 
perature and  of  atmospheric  moisture. 

More  modern  saccharimeters  are  provided  with  nikelin 
scales — an  alloy  somewhat  similar  to  German  silver  in 
appearance,  or,  best  of  all  with  glass  scales;  with  the  latter 
all  difficulties  of  this  kind  are  entirely  obviated. 

The  scale  may  be  right  in  some  places,  and  wrong  in 
others.  This  is  the  case  when  the  surfaces  of  the  quartz- 
wedges  are  not  perfectly  plane.  In  half-shade  saccharim- 
eters provided  with  double  compensation  wedges,  this 
cannot  occur,  as  any  inequality  would  be  noticed  at  once. 
In  other  saccharimeters,  the  scale  may  be  examined  by 
pure  sugar  solutions  of  different  densities,  by  means  of  the 
"  control  .tube  "  of  Schmidt  and  Haensch,  or  by  quartz 
plates. 

The  following  figures,  taken  from  a  table  calculated  by 
Schmitz,  show  the  number  of  grams  of  pure  sugar  which 
must  be  made  up  to  100  Mohr  c.c.  aqueous  solution  in 
order  to  show  the  corresponding  degree  on  a  saccharimeter 


42 


SUGAE  ANALYSIS 


having  26.048  grams  for  its  normal  weight  in  100  Mohr 
cubic  centimeters.* 


Polariscope 
Degrees. 

Grams  C.  P. 
Sugar  in 
100  c.c. 
Solution. 

Polariscopo 
Degrees. 

Grams  C.  P.  ! 
Sugar  .in 
100  c.c. 
Solution. 

Polariscope 
Degrees. 

Grams  C.  P. 
Sugar  in 
100  c.c. 
Solution. 

1 

0.260 

35 

9.097 

69 

17.954 

2 

0.519 

3G 

9.357 

70 

18.216 

3 

0.779 

37 

9.618 

71 

18.476 

4 

1.039 

38 

9.878 

72 

18  .  738 

5 

1.298 

39 

10.138 

73 

18.998 

6 

1.558 

40 

10.398 

74 

19.259 

7 

1.817 

41 

10.659 

75 

19.519 

8 

2.078 

42 

10.919 

76 

19.781 

9 

2.337 

43 

11.180 

77 

20.042 

10 

2.597 

44 

11.440 

78 

20.302 

11 

2.857 

45 

11.701 

79 

20.564 

12 

3.117 

46 

11.961 

80 

20.824 

13 

3.376 

47 

12.222 

81 

21.085 

14 

3.637 

48 

12.482 

82 

21.346 

15 

3.896 

49 

12.743 

83 

21.608 

16 

4.156 

50 

13.003 

84 

21.868 

17 

4.416 

51 

13.264 

85 

22.130 

18 

4.676 

52 

13.524 

86 

22.391 

19 

4.936 

53 

13.784 

87 

22.652 

20 

5.196 

54 

14.044 

88 

22.912 

21 

5.456 

55 

14.305 

89 

23.174 

22 

5.716 

56 

14.566 

90 

23.435 

23 

5.976 

57 

14.826 

91 

23.696 

24 

6.236 

58 

15.087 

92 

23.957 

25 

6.496 

59 

15.347 

93 

24.219 

26 

6.756 

60 

15.608 

94 

24.480 

27 

7.016 

61 

15.868 

95 

24.742 

28 

7.276 

62 

16.130 

96 

25.002 

29 

7.536 

63 

16.390 

97 

25.265 

30 

7.796 

64 

16.651 

98 

25.525 

31 

8.056 

65 

16.912 

99 

25.787 

32 

8.316 

66 

17.173 

100 

26.048 

33 

8.577 

67 

17.433 

34 

8.837 

68 

17.694 

*  C.  A.  Browne,  in  his  Handbook  of  Sugar  Analysis,  p.  118,  gives 
a  table  calculated  by  him  showing  the  effect  of  concentration  of  sucrose 
upon  polariscope  readings,  based  on  the  normal  weight  of  26.00  grams 
sucrose  in  100  metric  cubic  centimeters  at  20°  C.,  which  shows  some 
variations  from  the  table  of  Schmitz, 


POLAR1SCOPES  AND  ACCESSORIES  43 

This  method  of  testing  requires  a  separate  solution 
for  each  degree  of  the  scale  which  is  to  be  examined. 

If  the  weights  necessary  to  this  mode  of  examination 
are  not  available,  the  tests  can  be  made  by  dissolving  the 
normal  weight  of  chemically  pure  sugar  in  different  volumes 
of  water  at  the  normal  temperature.  Thus,  with  a  German 
saccharimeter  26.048  grams  of  such  sugar  will,  when  dis- 
solved— 

in  100  Mohr  c.c.  water  polarize  100.00° 
"105  "  "  "  95.23° 
11  110  "  "  "  90.90° 
"115  "  "  "  86.95° 
"120  "  "  "  83.33° 

If  a  control  tube  is  used,  but  few  solutions  are  needed, 
as  this  tube  is  so  arranged  that  it  can  be  lengthened  or 
shortened  at  will.  A  funnel  receives  the  superfluous  solu- 
tion when  the  tube  is  shortened,  and  a  scale  attached 
shows  the  length  of  the  column  in  millimeters.  A  simple 
calculation  gives  the  reading  which  will  be  shown  by  the 
polariscope  if  this  is  correct. 

Example. 

20.824  grams  of  pure  sucrose  made  up  to  100  Mohr  c.c. 
indicate,  when  read  in  a  200  m.m.  tube,  80°  on  a  saccharim- 
eter. 

200-7-80  =  2.5. 

Therefore,  shortening  the  control  tube  by  2.5  m.m.  must 
decrease  the  reading  on  the  saccharimeter  by  1°  provided 
that  the  scale  is  correct. 

Thus,  the  above  solution  should  read  in  a  tube: 

200  m.m.  80° 

197.5  m.m.  79° 

195.0  m.m.  78° 


44  SUGAR  ANALYSIS 

If  these  readings  are  not  obtained,  the  instrument  is 
incorrect  at  these  points,  and  the  necessary  corrections 
must  be  made  on  all  observations. 

It  is  also  necessary  to  verify  that  part  of  the  scale  which 
lies  to  the  left  of  the  zero  point.  This  can  be  done  by 
means  of  an  inverted  sucrose  solution  of  known  value. 
26.048  grams  of  chemically  pure  sucrose  are  dissolved  in 
water  and  made  up  to  100  Mohr  c.c.  If  the  polariscope 
scale  to  the  right  of  the  zero  mark  is  correct,  this  solution 
will  polarize  100°. 

A  part  of  this  solution  is  inverted  (see  Clerget's  Inversion 
Method),  the  inverted  solution  is  polarized,  and  the  usual 
calculation  made.  If  this  gives  the  value  =  100.00  that 
part  of  the  scale,  to  the  left  of  the  zero  point,  is  correctly 
graduated. 

Example:  Polarization  before  inversion  100.00 

Polarization  after  inversion  at  20°  C.  —  32.66 

100.00 
-32.66  100  X  132.66 


142.66-10 

If  this  portion  of  the  scale  is  not  correctly  graduated, 
but  that  part  of  the  scale  which  lies  between  zero  and  100° 
is  correct,  then  the  instrument  may  nevertheless  be  used 
for  obtaining  readings  of  inverted  solutions. 

All  that  is  necessary  is  to  insert  and  to  read  together 
with  the  inverted  solution,  a  dextro-rotatory  quartz  plate  of 
known  value.  The  difference  between  the  reading  of  this 
combination,  and  the  reading  of  the  quartz  plate  when 
read  alone,  represents  the  number  of  degrees  which  the 
inverted  solution  rotates  to  the  left. 

Example: 

Quartz  plate  +93.2 

Quartz  plate  +  inverted  solution.  (Calculated  for 
full  normal  weight  solution  in  200  m.m.  tube, 
at  20°  C.)  +79.2 

Inverted  Solution  —14.0 


POLARISCOPES  AND  ACCESSORIES  45 

Quartz  Plates.  If  quartz  plates  are  used  to  test  the 
accuracy  of  different  parts  of  the  scale  care  must  be  taken 
that  the  surfaces  of  the  plates  are  perfectly  plane,  that 
they  are  placed  in  the  optical  axis  of  the  instrument  and  at 
right  angles  to  it  and  that  the  plates  are  of  the  same  tem- 
perature as  the  quartz-wedges  of  the  saccharimeter.  The 
quartz  plates  must  of  course  have  been  carefully  tested  as 
to  their  accuracy  before  being  put  to  use.  Such  testing 
is  best  done  by  means  of  pure  sucrose  solutions;  another 
way  of  ascertaining  their  value,  i.e.,  the  amount  by  which 
they  rotate  a  plane  of  polarized  light,  is  to  measure  their 
thickness. 

This  measurement  can  be  effected  by  means  of  a  sphe- 
rometer.  This  consists  of  a  movable  screw  supported  in  the 
center  of  three  arms,  upon  which  the  apparatus  rests.  The 
screw  is  provided  at  its  lower  end  with  a  steel  point;  near 
its  upper  end  there  is  fastened  a  circular  plate  of  metal, 
the  circumference  of  which  is  divided  into  several  hundred 
equal  divisions.  Fastened  to  one  of  the  supporting  arms 
is  a  metal  bar,  also  bearing  a  graduation;  its  graduated 
edge  is  placed  at  right  angles  to  the  circular  disc. 

Parallel  to  the  latter,  and  attached  to  the  bar,  is  a 
sliding-scale  which  can  be  set  and  fastened  at  any  desired 
height.  The  graduation  of  the  sliding-scale  is  so  made, 
that  nine  of  its  divisions  correspond  to  ten  divisions  on 
the  disc. 

When  the  thickness  of  a  plate  of  quartz,  for  instance, 
is  to  be  measured,  the  screw  is  first  adjusted  in  such  a 
manner  that  it  shall  just  touch  the  perfectly  level  surface 
on  which  the  apparatus  has  been  placed. 

The  sliding-scale  is  next  fastened  on  the  bar  exactly 
on  a  level  with  the  circular  disc. 

Suppose  the  latter  to  bear  five  hundred  equal  divi- 
sions, and  the  graduated  bar  to  be  divided  into  halves  of 
a  millimeter.  The  threads  of  the  screw  are  so  cut  that 
one  complete  revolution  of  the  screw,  indicated  by  the 


46  SUGAE  ANALYSIS 

graduated  disc  fastened  to  it,  raises  the  screw  through 
one  half  of  a  millimeter.  To  effect  the  measurement  the 
screw  is  first  raised  sufficiently  so  as  to  allow  the  quartz 
plate  to  be  slipped  beneath  it;  when  this  has  been  done, 
the  screw  is  carefully  lowered  until  contact  is  secured 
between  its  point  and  the  quartz  plate.  From  the  num- 
ber of  revolutions  through  which  the  screw  has  been  turned, 
the  thickness  of  the  quartz  plate  is  determined;  with  a 
spherometer  graduated  as  here  assumed,  the  measure- 
ment will  be  exact  to  the  one  ten-thousandth  part  of  a 
millimeter. 

The  determination  of  the  value  of  quartz  plates  is  how- 
ever so  important  a  matter,  that,  if  it  is  at  all  possible  to 
secure  them,  only  quartz  plates  which  have  been  stand- 
ardized by  the  Bureau  of  Standards  or  which  have  been 
tested  against  some  plate  so  standardized  should  be 
used. 

As  quartz  suffers  modification  of  its  optical  value  by 
stress  or  strain,*  it  is  most  essential  that  all  quartz  control- 
plates  be  mounted  in  such  a  way  that  no  pressure  what- 
ever is  exerted  on  the  plate,  yet  they  must  not  lie  loose 
in  their  mounting. 

Polariscope  Tubes.  The  polariscope  tubes  must  be  of 
exactly  the  prescribed  length,  as  the  amount  of  deviation 
of  the  polarized  ray  produced  by  an  optically  active  sub- 
stance depends,  of  course,  among  other  conditions,  on  the 
length  of  the  column  of  the  substance  which  it  traverses. 
The  length  of  tubes  can  readily  be  determined  by  measur- 
ing them  with  a  metal  rod  made  of  the  standard  length. 
The  ends  of  the  polarization  tubes  must  be  ground  perfectly 
plane-parallel. 

Where  a  great  number  of  polarizations  must  be  made, 
Pellet's  tube  for  continuous  polarization  can  be  advan- 
tageously employed. 

*Wiechmann,  School  of  Mines  Quarterly,  Vol.  XX,  1899,  The 
Optical  Behavior  of  Quartz  under  Stress. 


POLARISCOPES  AND  ACCESSORIES  47 

This  tube  is  provided  at  each  end  with  a  metal  tube  of 
small  diameter,  placed  at  right  angles  to  the  main  tube. 
One  of  the  projecting  tubules  is  connected  with  a  funnel 
through  which  the  solution  which  is  to  be  polarized  is 
introduced,  the  other  tubule  serves  for  the  escape  of  the 
liquid  when  no  longer  needed.  The  tube  is  filled  by  dis- 
placement with  the  various  solutions  to  be  tested,  about 
20  to  40  c.c.  of  solution  being  requisite  for  the  purpose. 
The  readings  are  taken  as  soon  as  the  field  appears  per- 
fectly clear  and  uniform. 

A  convenient  form  of  polariscope  tube  has  its  ends 
somewhat  enlarged  so  that  any  air  bubbles  which  may 
be  introduced  on  filling  the  tube  do  not  lie  in  the  field  of 
vision  and  interfere  with  the  readings. 

The  cover  glasses  of  the  polarization  tubes  must  be  made 
of  perfectly  white  glass,  and  must  be  free  from  scratches. 

Another  point  to  be  borne  in  mind  is  the  fact  that  the 
glass  covers  of  the  polarization  tubes  may  be  optically 
active,  either  by  nature  of  the  glass,  by  being  screwed  down 
too  tight,  or  by  not  having  both  surfaces  perfectly  parallel. 

To  guard  against  the  first  of  these  sources  of  error  the 
covers  should  be  tested  by  placing  distilled  water  in  the 
tube  and  noting  the  absence  of  any  optical  activity.  Non- 
parallelism  of  the  surfaces  can  be  readily  recognized  by 
taking  a  glass  cover  between  two  fingers  and  rotating  it 
rapidly,  at  the  same  time  locking  through  it  at  some  fixed 
object.  If  the  latter  seems  to  be  moving,  the  glass  is  not 
plane-parallel,  and  should  be  rejected. 

The  test  can  also  be  made  with  a  simple  apparatus 
devised  for  the  purpose.  A  disc  which  can  be  rotated  on 
its  axis  is  placed  between  two  black  screens  each  one  of 
which  is  provided  with  a  small  aperture. 

A  light  is  placed  behind  one  of  these  screens  and  some 
of  the  light  rays  are  permitted  to  fall  upon  the  glass  cover 
which  has  been  placed  on  the  movable  disc. 

The  observer  on  looking  through  the  aperture  in  the 


48  SUGAR  ANALYSIS 

second  screen  will  see  two  images  of  the  source  of  light, 
caused  by  reflection  from  the  lower  and  the  upper  faces 
of  the  glass  cover. 

On  rotating  the  disc  these  two  images  will  retain  their 
relative  position  unchanged  only  when  the  cover  has  been 
cut  perfectly  plane-parallel.  If  the  images  appear  to  change 
their  relative  position,  the  cover  glass  should  be  rejected. 

To  reduce  the  chance  of  accidental  pressure  on  the  cover 
glasses  to  a  minimum  it  is  recommended  that  the  caps 
closing  the  ends  of  the  polariscope  tubes  be  provided  with 
bayonet  catches  instead  of  being  screwed  into  place  as  is 
customary. 

Sources  of  Light.  The  light  used  for  polariscopic  work 
may  be  furnished  either  by  gas,  alcohol,  oil,  acetylene  or 
electricity  as  all  of  these  emit  white  light. 

Of  course  each  one  of  these  light  sources  calls  for  its 
own  style  of  lamp,  burner,  or  bulb  to  yield  the  best  results. 

If  illuminating  gas  be  used,  Argand  triple-burners  having 
flat,  not  circular,  flames,  may  be  employed.  With  the  same 
illuminant,  incandescent  light  mantles  give  good  results. 
Where  electric  power  is  available,  a  50  C.P.  or  a  100  C.P. 
spiral  filament  bulb  gives  satisfaction. 

It  is  important  to  note  that  with  the  Ventzke  saccharim- 
eters  a  layer  1.5  cm.  thick  of  a  6%  solution  of  potassium 
dichromate  must  be  used  as  a  ray  filter,  as  otherwise,  color- 
less or  very  light-colored  sugar  solutions  will  make  an  even 
adjustment  of  both  halves  of  the  saccharimeter-field  dif- 
ficult, if  not  impossible.  This  phenomenon  is  due  to  a 
slight  difference  in  the  optical  qualities  of  sugar  and  the 
quartz.  If  the  light-filter  is  not  used  a  normal  sucrose 
solution  will  read  0.12°  Ventzke  too  high.  If  an  instrument 
of  the  Laurent  type  is  used,  a  suitable  monochromatic 
light  must  be  provided.  Various  types  of  such  lamps 
are  in  use,  but  it  has  been  found  to  be  a  difficult  matter 
to  obtain  an  intensive  illumination  which  shall  prove 
constant  for  a  considerable  length  of  time. 


POLARISCOPES  AND  ACCESSORIES  49 

A  device  due  to  H.  W.  Wiley  has  given  satisfaction  in 
this  respect.  Following  is  a  description  of  this  apparatus.* 

It  consists  essentially  of  two  wheels  with  platinum  gauze 
perimeters  and  platinum  wire  spokes,  driven  by  a  clock-work, 
and  mounted  by  supports.  The  sodium  salt,  chlorid  or  bro- 
mid,  in  saturated  solution,  is  placed  in  porcelain  crucibles,  to 
such  a  depth  that  the  rims' of  the  platinum  wheels  dip  beneath 
the  surface  as  they  revolve.  The  salt  is  volatilized  by  the 
lamp.  By  means  of  crossed  bands  the  wheels  are  made  to 
revolve  in  opposite  directions.  The  solution  of  the  salt, 
which  is  taken  up  by  the  platinum  net  work  of  the  rim  of 
the  wheel,  thus  has  time  to  become  perfectly*  dry  before  it 
enters  the  flame,  and  the  sputtering  which  a  moist  salt  would 
produce  is  avoided.  At  every  instant,  by  this  arrangement, 
a  minute  fresh  portion  of  salt  is  introduced  into  the  flame 
with  the  result  of  making  a  perfectly  uniform  light,  which 
can  be  used  for  hours  without  any  perceptible  variation. 
The  mechanism  of  the  apparatus  is  so  simple  that  no  further 
description  is  necessary.  The  polariscope  should  be  so 
directed  toward  the  flame  as  to  bring  into  the  field  of  vision 
its  most  luminous  part.  The  platinum  wheels  are  adjustable 
and  should  be  so  arranged  as  to  produce  between  them  an 
unbroken  yellow  flame.  The  wheels  are  eight  cm.  in  diameter 
and  driven  at  a  rate  to  make  one  revolution  in  six  to  ten 
minutes. 

F.  Dupont  has  suggested  sodium  chloride  and  sodium 
tribasic  phosphate,  fused  together  in  molecular  proportions, 
as  an  excellent  combination  for  the  emission  of  monochro- 
matic light. 

The  scale  of  a  polariscope  is  illuminated  either  by  trans- 
mitted light,  by  reflected  light,  or  by  means  of  a  separate 
little  electric  light  bulb  which  is  switched  on  and  off  by 
*he  operator  as  required  to  make  the  readings. 

Whatever  be  the  source  of  light  care  must  be  taken  that 

*  Journal  American  Chemical  Society,  Vol.  XV,  p.  121. 


50  SUGAR  ANALYSIS 

a  clear  bright  illumination  of  the  field  is  secured  and  that  the 
source  of  light  be  so  placed  that  any  heating  of  the  instru- 
ment is  avoided.  The  source  of  light  should  be  at  least 
200  m.m.  from  the  end  of  the  instrument  and  should  be 
screened  therefrom  by  a  partition  provided  with  an  open- 
ing only  sufficiently  large  to  permit  the  passing  of  the 
light-rays  to  the  saccharimeter. 


CHAPTER  IV 
SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS 

Sampling.  Before  taking  up  the  analytical  determina- 
tion of  sucrose  it  is  necessary  to  say  a  few  words  on  the 
securing  of  correct  samples,  that  is  to  say  on  the  obtain- 
ing of  samples  representative  of  the  cargo. 

Samples  of  sugar  are  drawn  with  a  long  steel  rod,  pointed, 
and  with  a  groove  on  one  side.  The  package  is  pierced, 
the  trier  inserted,  rotated  completely  and  withdrawn. 
The  sample  filling  the  hollow  in  the  trier  is  removed  and 
put  into  a  can. 

Following  are  the  U.  S.  Government  directions  (1907) 
for  the  sampling  of  sugars  and  molasses. 

"  Art.  3.  All  sampling  shall  be  done  at  the  time  of 
weighing.  In  sampling  imported  raw  sugars  a  general 
sample  shall  be  taken;  that  is,  each  cargo  shall  be  sampled 
without  regard  to  marks,  except  as  provided  in  Articles 
12  and  13.  In  the  event  that  a  cargo  is  consigned  to  two 
or  more  consignees,  any  consignee's  sugar  shall  be  treated  as 
a  separate  cargo,  provided  separate  entry  be  made  by  such 
consignee.  A  separate  general  sample  shall  also  be  taken 
of  (a)  wet  sugar,  (6)  damaged  sugar  not  wet,  (c)  ship  sweep- 
ings, (d)  dock  sweepings.  In  taking  the  general  sample 
100%  of  the  packages  shall  be  samples.  In  order  to 
prevent  any  unnecessary  labor  and  inconvenience  in 
obtaining  the  sample,  the  inspector  shall  direct  that  the 
packages  when  discharged  from  the  vessel  upon  the  wharf 
shall  be  so  placed  that  the  sampler  can  readily  obtain  a 
100%  sample.  All  ship  and  dock  sweepings  shall  be  sampled 
before  the  sampler  completes  his  half  day's  work. 

51 


52 


SUGAR  ANALYSIS 


"  Art.  4.  In  the  treatment  of  sugars  under  these  regula- 
tions great  care  will  be  taken  by  samplers  and  other  apprais- 
ing officers  to  prevent  the  drying  out  of  the  samples.  All 
the  sugar  buckets  in  the  possession  of  a  sampler  shall  be 
either  entirely  filled  or  entirely  empty,  with  the  exception 
of  one  bucket  for  each  general  sample.  The  tag  on  each 
bucket  must  indicate  the  character  of  the  sugar  and  the 
particular  half  day  on  which  its  contents  were  drawn.  The 
covers  of  the  buckets  must  be  kept  carefully  closed,  except 
when  momentarily  opened  to  receive  the  sample.  The 
buckets  shall  be  made  of  heavy  galvanized  iron  and  have  a 
height  of  31.5  centimeters  and  a  diameter  of  18.5  centi- 
meters. *  *  * 

"  Art.  5.  The  sugar  triers  used  shall  have  the  following 
dimensions : 


Short  Trier. 
Centimeters. 

Long  Trier. 
Centimeters. 

Barrel  Trier. 
Centimeters. 

Length  ov6r8/ll 

40  6 

152  4 

104  0 

Length  of  spoon  

22.9 

132.1 

91.4 

Length  of  shank  

17.8 

20.3 

12.7 

Length  of  handle  
Width  of  spoon    

26.7 

2.7 

38.1 
2.5 

30.5 
2.5 

Depth  of  spoon  
Diameter  of  handle  

0.8 

3.8 

1.3 

3.8 

1.1 

3.8 

"  Art.  6.  m  Sugar  in  hogsheads  and  other  wooden  packages 
shall  be  sampled  by  putting  the  long  trier  diagonally  through 
the  package  from  chime  to  chime,  one  trierful  to  constitute 
a  sample,  except  in  small  lots,  when  an  equal  number  of 
trierfuls  shall  be  taken  from  each  package  to  furnish  the 
required  amount  of  sugar  necessary  to  make  a  sufficient 
sample.  In  the  sampling  of  baskets,  bags,  ceroons,  and 
mats  the  short  trier  shall  be  used,  care  being  exercised  to 
have  each  sample  represent  the  contents  of  the  package. 
The  greatest  precaution  shall  be  taken  that  the  samples 
from  each  class  of  packages  shall  be  kept  separate  and  be 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    53 

uniform  in  quantity.  When  the  hard  condition  of  the 
sugar  renders  the  use  of  the  short  trier  impracticable  the 
sampler  in  charge  shall  notify  the  appraiser  immediately 
and  await  his  instructions.  The  keys  of  the  sugar  buckets 
shall  be  in  possession  of  the  examiner  of  the  appraiser's 
office,  who  shall  have  sole  custody  of  such  keys.  *  *  * 

"  Art.  13.  When  practicable  all  refined  sugars  shall  be 
sampled  with  a  trier  specially  provided  for  that  purpose,  and 
such  percentage  shall  be  sampled  as  in  the  judgment  of  the 
examiner  or  sampler  in  charge  will  afford  a  fair  representa- 
tion of  the  mark.  When  there  is  doubt  whether  a  package 
of  sugar  is  raw  or  refined,  or  whether  a  raw  sugar  is  above  or 
below  No.  16  Dutch  standard  in  color,  such  package  shall 
be  sampled  in  not  less  than  two  places  to  fairly  represent  the 
contents,  and  such  samples  shall  aggregate  not  less  than 
eleven  ounces.  The  package  shall  be  numbered  by  the 
weigher  and  weighed  separately,  and  the  weigher's  return 
shall  show  the  number  and  weight  of  such  package. 

"  Art.  14.  The  utmost,  care  must  be  taken  to  keep  all  the 
apparatus  used  in  the  process  of  sampling  sugar  clean  and 
absolutely  dry.  *  *  * 

"  Art.  15.  Of  importations  of  molasses,  as  near  as  pos- 
sible to  100%  of  the  packages  shall  be  sampled.  If  any 
package  or  packages  invoiced  as  molasses  shall,  in  the 
judgment  of  the  sampling  officer,  have  the  appearance  of 
sirup  of  cane  juice,  a  separate  sample  from  each  such  package, 
properly  labeled  as  to  mark  and  character,  shall  be  taken 
for  examination  as  hereinafter  provided. 

"  Art.  16.  In  drawing  samples  of  molasses  care  shall  be 
taken  to  secure  a  fair  representation  and  an  equal  amount 
of  the  contents  from  each  package.  Packages  of  the  same 
size  shall  be  sampled  in  groups  of  not  more  than  25 ;  samples 
from  all  of  the  packages  of  each  group  being  put  into  a 
bucket.  *  *  *  Molasses  discharged  from  tank  vessels 
shall  be  sampled  as  it  is  pumped  from  the  tanks,  a  sample 
of  uniform  quantity  being  drawn  at  either  regular  intervals 


54  SUGAE  ANALYSIS 

of  approximately  fifteen  minutes  or  for  every  5,000  gallons 
discharged. 

"  Art.  17.  Inasmuch  as  the  absorption  of  sea  water  or 
moisture  reduces  the  polariscopic  test  of  sugar,  there  shall 
be  no  allowance  on  account  of  increased  weight  of  sugar 
importations  due  to  unusual  absorption  of  sea  water  or  of 
moisture  while  on  the  voyage  of  importation,  and  the  pro- 
visions of  Article  1276  of  the  Customs  Regulations  of  1899 
shall  not  apply  to  sugar  importations.  That  portion  of 
the  cargo  claimed  by  the  importer  to  have  absorbed  sea 
water  or  moisture  on  the  voyage  of  importation  shall  be 
sampled,  tested,  and  classified  separately.  This  claim  must 
be  made  at  the  time  of  weighing.  Special  care  must  be 
taken  that  such  sugars  are  sampled  so  as  to  fairly  represent 
the  contents  of  the  packages."* 

When  it  is  not  feasible  to  make  a  separate  analysis  of 
every  mark  in  a  lot  a  representative  sample  must  be  pre- 
pared; this  can  be  done  in  the  following  manner.  Fix 
upon  some  definite  quantity  by  weight  as  the  unit  weight. 
Weigh  out  this  amount,  proportionate  to  the  number  of 
packages  in  each  mark,  and  place  in  a  well-closed  jar. 

For  example,  suppose  a  lot  of  sugar  contained  four 
marks,  A,  B,  C,  and  D,  and  that: 

Mark  A  =  1000  packages 
"     B=  200        " 
"     C=   350 
"    D=     70 

Then  take  from: 

A  =  100  grams 
B  =  20     " 
C=  35     " 
D=     7    " 

*  For  a  full  account  of  sampling  raw  sugars  in  different  countries 
see  Wiechmann,  Int.  Sugar  Jour.  Vol.  IX,  pp.  18-28. 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    55 

When  the  composite  sample  is  completed  mix  it  thor- 
oughly and  proceed  with  the  analysis. 

As  some  lots  come  in  mixed  packages,  for  instance  partly 
in  hogsheads,  bags,  tierces  and  barrels  a  certain  relation 
between  these  is  sometimes  assumed. 

1  hogshead  =  2  tierces 
1  "  =8  barrels 
1 


Besides  the  packages  mentioned  sugar  is  also  shipped  in 
baskets,  mats  and  ceroons. 

Dutch  Standard.  The  Dutch  Standard  referred  to  in 
the  U.  S.  Government  Regulations  consists  of  a  number  of 
samples  of  cane  sugar  which  range  from  dark  brown  (No.  7) 
to  almost  white  (No.  25)  in  color.  They  are  prepared  and 
put  up  in  glass  bottles  in  Holland  under  the  direction  of 
the  Netherlands  Trading  Society.  The  samples  are  renewed 
each  year  and  serve  as  standards  in  the  assessment  of  duties. 

A.  Determination  of  Sucrose  in  the  Absence  of  Other 
Optically  Active  Substances.  Method  I.  With  use  of 
balance.  Sugar  samples  for  analysis  should  be  kept  in 
cans,  boxes  or  glass  vessels  which  must  be  practically  air- 
tight. 

When  such  samples  are  brought  into  the  laboratory 
from  out-of-doors  or  from  a  cold  store-room  they  should 
be  kept  in  the  laboratory  for  a  sufficient  time  to  allow 
their  contents  to  acquire  the  laboratory  temperature  in 
order  that  no  moisture  may  condense  on  the  cold  sugar. 

The  sample  should  then  be  quickly  but  thoroughly 
mixed;  if  the  sugar  contains  lumps  it  must  first  be  thor- 
oughly crushed  and  only  then  mixed. 

The  normal  weight  of  the  sample,  26.000  grams,  if  the 
metric  c.c.  flask,  26.048  grams  if  the  Mohr  c.c.  flask  is  used, 
is  weighed  out  in  the  tared  sugar-cup  provided  for  the 
purpose,  the  sugar  is  then  partially  dissolved  and  washed 
into  a  100  c.c.  flask  with  distilled  water  or  with  clear  water 


56  SUGAR  ANALYSIS 

which  is  optically  inactive,  and  its  solution  is  completed 
in  the  flask.  Not  more  than  75  c.c.  or  80  c.c.  at  most, 
should  be  used  to  bring  this  about. 

If  the  sugar  solution  is  sufficiently  light  in  color  but 
possibly  somewhat  opalescent,  a  few  drops  of  alumina 
cream  *  are  added,  and  the  volume  of  the  solution  is  made 
up  with  water  to  the  100  c.c.  mark  on  the  neck  of  the  flask. 

If  the  sugar  solution  requires  decolorization,  a  clarifying 
reagent  must  be  added  before  the  volume  of  the  solution  is 
brought  up  to  100  c.c. 

The  reagent  used  for  this  purpose  is  known  as  basic 
acetate  of  lead,  or  subacetate  of  lead.f  It  is  very  important 
that-  sufficient  of  this  reagent  is  added  to  effect  the  desired 
clarification,  but  equally  important  that  the  addition  of 
an  excess  of  the  reagent  be  avoided,  for  the  volume  of  the 
precipitate  which  is  formed  causes  an  error  in  polarization. 

Experience  must  guide  as  to  the  proper  amount  to  be 
used.  If  the  amount  added  is  sufficient,  the  precipitate 
formed  will,  as  a  rule,  settle  quickly;  in  any  case,  one 
additional  drop  of  the  reagent  is  put  into  the  solution. 
If  this  disappears  in  the  solution,  the  quantity  of  the  sub- 
acetate  of  lead  added  has  been  insufficient  and  an  additional 
amount  must  be  given;  if,  on  the  other  hand,  the  drop  can 

*  Alumina  cream  is  made  by  dissolving  aluminum  sulphate  or 
aluminum  chloride  in  a  considerable  amount  of  cold  water  and  the 
alumina  hydrate  precipitated  by  the  addition  of  ammonic  hydrate. 
The  precipitate  is  then  thoroughly  washed  until  all  acid  has  been 
removed,  and  the  creamy  alumina  hydrate,  suspended  in  water,  is 
kept  for  use. 

f  Subacetate  of  lead  is  prepared  as  follows:  Take  3  parts  by  weight 
of  acetate  of  lead,  1  part  by  weight  of  oxide  of  lead  and  10  parts  by 
weight  of  water.  Boil  these  together — the  water  being  added  grad- 
ually, until  practically  all  has  been  dissolved  to  a  turbid  solution. 
This  is  then  set  aside  to  settle  and  is  finally  filtered.  Subacetate  of 
lead  must  show  an  alkaline  reaction  to  litmus,  but  it  must  not  redden 
phenolphthalein.  Its  specific  gravity  must  be  about  1.25.  In  place 
of  the  acetate  of  lead  and  the  oxide  of  lead,  solid  subacetate  of  lead 
may  be  used  for  making  this  solution. 


SUCEOSE  DETERMINATION  BY  OPTICAL  ANALYSIS    57 

be  traced  through  the  solution  as  it  flows  along  the  glass 
of  the  flask,  no  more  is  required. 

In  some  instances  a  few  drops  of  alumina  cream  may 
have  to  be  used  in  addition  to  the  subacetate  of  lead  in 
order  to  secure  solutions  entirely  free  from  opalescence. 

When  the  clarifying  reagent  or  reagents  have  been  added, 
the  solution  is  made  up  to  the  100  c.c.  mark  on  the  flask, 
taking  care  that  the  lowest  point  of  the  meniscus  of  the 
liquid  just  touches  that  mark.  The  contents  of  the  flask 
are  then  well  shaken  and  the  entire  solution  poured  at  once 
on  a  perfectly  dry  filter. 

The  first  20  cubic  centimeters  of  the  filtrate  should  be 
entirely  rejected  and  only  a  perfectly  bright  and  clear 
filtrate  used  for  polarization.  During  said  filtration  both 
funnel  and  beaker  should  be  covered  to  avoid  concentration 
of  solution  by  evaporation. 

A  200  m.m.  polariscope  tube  is  then  filled  with  the 
solution  and  the  readings  made.  Several  readings  must 
be  made  on  each  solution  tested  and  the  average  of  all  but 
the  first  reading — which  is  discarded,  is  recorded. 

Should  the  solution  be  too  dark  in  color  to  admit  of  its 
being  polarized  in  the  200  m.m.  tube  the  reading  should  be 
made  in  a  100  m.m.  tube  and  the  polarization  doubled. 

The  use  of  specially  prepared  bone-black  dust  *  as  a 
decolorant  for  very  dark  colored  solutions  is  sometimes 
resorted  to,  but  it  should  not  be  used  unless  it  is  absolutely 
impossible  to  do  without  it. 

The  saccharimeters  now  in  universal  use  record  the 
amount  of  sucrose  in  per  cent,  provided  the  normal  weight 
of  the  sample  has  been  used,  and  the  reading  has  been 
effected  in  a  200  m.m.  tube;  if  a  100  m.m.  tube  has  been 
used,  the  reading  must  be  doubled. 

*  Warm  for  several  hours  with  hydrochloric  acid  to  dissolve  the 
phosphate  and  carbonate  of  lime;  then  wash  with  boiling  water  till 
all  traces  of  chlorine  are  removed;  dry  at  about  125°  C.,  and  keep 
in  a  well-closed  jar. 


58  SUGAR  ANALYSIS 

If  for  any  reason  the  normal  weight  has  not  been  taken, 
a  simple  calculation  will  serve  to  figure  the  percentage  of 
sucrose  in  the  sample.  Suppose,  for  instance,  that  18.000 
grams  had  been  weighed  for  polarization  and  that  these 
were  dissolved  up  to  100  c.c.  A  polarization  of  this  solution 
in  a  200  m.m.  tube  =  62.00. 

As  a  rotation  of  one  degree  represents  0.26048  gram 
sucrose  (Mohr  flask)  there  are  contained  in  the  sample 
0.26048X62  =  16.14976  grams  pure  sucrose. 

Hence  18.000  :  16.14976::  100  :  x.    x  =  89.72. 

Therefore  the  sample  contains  89.72%  sucrose. 

A  more  direct  way  cf  figuring  this  is  by  means  of  the 
formula : 

PXTF' 

—  =per  cent  sucrose. 

P  =  polarization  of  the  solution; 
W  =  normal  weight  of  the  instrument  used ; 
W  =  weight  of  substance  taken  for  polarization. 

,       62.0X26.048 
Example.  —  =  89.72. 

lo.U 

Results  so  obtained  can  be  verified  by  calculating  the 
amount  of  sugar  which  would  be  necessary  in  order  to 
indicate  100°  on  the  polariscope.  This  is  known  as 
Scheibler's  method  of  "One  hundred  polarization." 

Example.  In  the  case  just  discussed,  a  polarization  of 
89.72  required  26.048  grams  of  the  sugar:  how  much 
will  be  required  to  produce  a  rotation  of  100°  on  the 
instrument? 

89.72  :  26.048::  100  :  x.  £  =  29.0325. 

Therefore  29.0325  grams  of  this  sample  are  polarized 
in  the  usual  manner,  and  if  they  indicate  100%  the  result 
previously  obtained,  is  correct, 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    59 

Table  VII,  by  Scheibler,  obviates  the  necessity  of  this 
calculation,  showing  at  once  the  amount  that  must  be 
used. 

Method  II.  Without  use  of  Balance.  The  percentage  of 
sucrose  in  a  sample  can  also  be  obtained  without  making 
a  weighing.  A  solution  is  made  and  the  specific  gravity 
of  the  solution  is  determined,  either  directly  by  a  specific- 
gravity  hydrometer  or  else  by  some  other  hydrometer 
(Brix,  Baume),  the  readings  of  which  are  translated  into 
the  corresponding  specific  gravity  (Table  I). 

The  polarization  of  the  solution  is  then  made,  and  the 
percentage  of  sucrose  calculated  by  the  formula: 

PX.2605 
~.      D       ' 

in  which  S  =  percentage  of  sucrose, 

P  =  polarization  of  the  solution, 
D  =  specific  gravity. 

If  the  solution  needs  clarifying,  it  is  placed  into  a  grad- 
uated flask,  the  amount  of  basic  acetate  of  lead  solution 
that  is  added,  is  noted,  and  the  reading  increased  in  propor- 
tion. 

Example.     Specific  gravity  of  solution,  1.0909; 
Polarization  of  solution  =  35.0. 

To  100  c.c.  of  solution  added  5  c.c.  basic  acetate  of 
lead  solution;  this  corresponds  to  5%  of  35.0  =  1.75. 
Hence  corrected  polarization  =  36. 75  per  cent. 

36.75  X.26C5 


1.0909 


=  8.77  per  cent  sucrose. 


This  calculation  can  be  avoided  by  consulting  Table 
VI.     This  table  is  used  in  the  following  manner: 

Example.     Corrected  specific  gravity  =  1.0339; 
Polarization  =25.0, 


60  SUGAR  ANALYSIS 

In  a  line  with  the  specific  gravity  1.0339,  and  in  the 
horizontal  column  marked  2,  is  found  the  number  .504. 
This  multiplied  by  10  =  5.040. 

In  a  line  with  the  specific  gravity  1.0339,  and  in  the 
column  marked  5,  is  found  the  number  1.260. 

Adding  these  values,      5.040 

1.260 

Percentage  of  sucrose  =  6.300 

The  simple  polarization  of  a  sugar,  syrup,  liquor,  magma, 
or  sweet-water  shows  the  percentage  of  sucrose  in  the  sample 
as  it  is.  Sometimes,  however,  it  is  necessary  to  know 
what  this  percentage  would  be  if  the  water  in  the  sample 
were  removed;  in  other  words,  it  may  be  desirable  to 
ascertain  the  percentage  of  sucrose  in  the  li  dry  substance." 

Coefficient  of  Purity,  or  exponent,  is  the  term  which  is 
applied  to  this  value.  There  are  several  ways  in  which 
this  can  be  determined.  The  most  accurate  method 
undoubtedly,  but  also  the  one  which  demands  most  time 
for  its  execution,  is  the  following. 

Method  I.  Determine  polarization  of  the  normal  weight 
of  the  sample  as  previously  described.  Determine  the 
percentage  of  water  by  drying  to  constant  weight.  Sub- 
tract the  percentage  of  water  from  100,  and  divide  the  re- 
mainder into  the  polarization  multiplied  by  100. 

Example.     Polarization  of  syrup,  33.00; 

Water  in  syrup,  per  cent,      24.16. 

100.00 

24.16  3300^75.84=43.5 

75.84 

Polarization  on  dry  substance  =  43.5. 

Method  II.  Determine  polarization  of  the  normal 
weight  of  the  sample  as  previously  described.  Determine 
the  degree  Brix  of  the  sample.  Correct  for  temperature 
(Table  III). 


SUCEOSE  DETERMINATION  BY  OPTICAL  ANALYSIS    61 


Calculate  polarization  on  the  dry  substance  by  the 
formula : 

Pol.  X 100 
Degree  Brix ' 

Example.     Polarization,  40.00; 

Density,  50°  Brix  at  24°  C.; 

Correction  for  temperature, +0.49 
Degree  Brix  corrected  for  temperature, 

=  50.49. 

100.00-5-50.49  =  1.9806,  factor; 

40.00X1.9806  =  79.22,  polarization  on  the  dry  substance, 
or  coefficient  of  purity. 

Method  III.  Ventzke's  Method.  Prepare  a  solution 
of  the  sugar  which  shall  have  the  specific  gravity  1.100 
at  17.5°  C.  Take  the  reading  of  this  solution  in  a  200 
m.m.  tube.  This  polariscope  reading  shows  at  once  the 
percentage  of  pure  sugar  in  the  dry  substance.  This  is 
the  case,  because  a  solution  made  by  dissolving  26.048 
grams  of  chemically  pure  sugar  in  water  up  to  100  Mohr 
c.c.  has  the  specific  gravity  of  1.1000  at  the  temperature  of 
17.5°  C.,  and  a  column  of  this  solution  200  m.m.  in  length, 
indicates  100%  in  polariscopes  of  the  German  type. 

The  following  table  prepared  by  Gerlach  shows  the  specific 
gravity  of  the  above  solution  at  the  temperatures  given: 


Temper- 
ature. 
0  C. 

Specific 
Gravity. 

Temper- 
ature. 
°C. 

Specific 
Gravity. 

Temper- 
ature. 
°C. 

Specific 
Gravity. 

0 

1  .  10324 

16.5 

1  .  10028 

23 

1.09834 

5 

1.10266 

17 

1  .  10014 

24 

1.09802 

10 

1  .  10192 

17.5 

1  .  10000 

25 

1.09770 

11 

1  .  10168 

18 

1.09986 

26 

1.09736 

12 

1  .  10144 

18.5 

1.09972 

27 

1.09702 

13 

1.10119 

19 

1.09957 

28 

1.09669 

14 

1  .  10095 

19.5 

1.09943 

29 

1.09635 

15 

1  .  10071 

20 

1.09929 

30 

1.09601 

15.5 

1  .  10057 

21 

1.09897 

16 

1  .  10043 

22 

1.09865 

62  SUGAB  ANALYSIS 

As  the  preparation  of  a  solution  which  is  to  have  a 
certain  specific  gravity  at  a  certain  temperature  is  apt 
to  prove  a  tedious  operation,  the  following  modification 
of  Ventzke's  method  will  prove  serviceable: 

If  the  temperature  at  which  the  solution  is  prepared 
is  not  the  normal  temperature,  a  correction  must  be  made 
(Table  II). 

This  correction  must  be  subtracted  from  the  reading 
of  the  specific-gravity  hydrometer  if  the  temperature  is 
lower  than  the  normal,  and  added,  if  it  is  above  the  nor- 
mal temperature. 

The  polarization  obtained  in  the  200  m.m.  tube  must 
then  be  multiplied  by  the  factor  corresponding  to  the 
corrected  specific  gravity  (Table  IV). 

Method  IV.  Casamajor's  Method.  Determine  the 
specific  gravity  or  the  degree  Brix  of  the  solution.  Cor- 
rect for  temperature  if  necessary  (Table  III).  Determine 
the  polarization  of  this  solution  and  multiply  the  polariza- 
tion by  the  factor  corresponding  to  the  degree  Brix  (Table 
V). 

Example.     Polarization  of  solution  =  6 1.2; 
Brix,  =  15.5°  at  22°  C.; 
Correction  for  temperature, +0.31 
Corrected  degree  Brix  =  15. 81; 
Factor  corresponding  to  15.8°  Brix  is  1.548 

61.2X1.548  =  94.74,  which  is  the  polarization  on  the 
dry  substance,  the  coefficient  of  purity. 

The  coefficient  of  purity  obtained  by  Method  I  (where 
the  percentage  of  water  is  obtained  by  actual  drying  out), 
is  called  the  "  true  "  coefficient  of  purity;  if  hydrometers 
are  resorted  to,  as  in  Methods  II,  III,  and  IV,  the  resulting 
coefficient  is  called  the  "  apparent  "  coefficient  of  purity. 

If  a  syrup  or  a  molasses  has  been  analyzed,  the  results 
of  the  analysis  can  easily  be  calculated  into  equivalents 
on  the  dry  substance  in  the  following  manner: 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    63 

The  reciprocal  of  the  degree  Brix  (that  is,  the  quotient 
obtained  by  dividing  100  by  the  degree  Brix),  gives  a 
factor  by  which  the  percentage  of  sugar,  invert  sugar, 
and  ash  must  be  multiplied  in  order  to  reduce  them  to 
the  basis  of  dry  substance. 

Example.     A  syrup  of  80.4°  Brix  shows  on  analysis: 

Polarization,  31.2; 
Invert  sugar,  12.5; 
Ash,  6.0. 

100-7-80.4  =  1.2437. 

On  Dry  Substance. 

Hence:  Polarization,    31.2X1.2437  =  38.80  per  cent 

Invert  sugar,   12.5X1.2437  =  15.55 

Ash,  6.0X1.2437=   7.46 

Non-ascertained  (by  difference)  =38.19         " 


100.00  per  cent. 

If  sucrose  has  to  be  determined  in  a  molasses,  a  syrup, 
or  in  sweet-water,  the  calculation  of  the  result  to  dry  sub- 
stance can  be  avoided  by  aid  of  Table  VIII. 

This  table  has  been  calculated  for  use  with  the  German 
polariscopes  (normal  weight  26.048  grams).  It  presupposes 
the  addition  of  10%  by  volume  of  basic  acetate  of  lead 
to  the  sucrose  solution  examined,  and  in  its  preparation 
the  variable  specific  rotatory  power  of  sucrose  has  also  been 
taken  into  account. 

The  use  of  the  table  is  very  simple. 

Example.  Density  of  a  sugar  solution,  22.0°  Brix. 
Polarization  (after  using  10%  by  volume  of  basic  acetate 
of  lead  solution  for  clarifying),  60.3. 

In  column  headed  22.0°  Brix,  and  opposite  to  the  num- 
ber 60  in  the  column  headed  "  Polariscope  degrees,"  we 
find  15.72%  sucrose.  Then,  turning  on  the  same  page  to 
the  division  for  tenths  of  a  degree,  in  the  section  headed 


64  SUGAR  ANALYSIS 

"  Per  cent  Brix  from  11.5  to  22.5,"  there  is  given  opposite 
to  0.3  Brix  the  value  0.08%  sucrose. 

Hence    60.0°  =  15.72  per  cent. 
0.3°=  0.08 


60.3°  =  15.80  per  cent  sucrose. 

Sucrose  in  Fill  Mass.  Weigh  out  250  grams  of  the 
massescuite,  add  250  grams  of  water,  carefully  dissolve 
all  crystals  and  insure  a  thorough  mixing  of  the  sample. 
Determine  and  note  the  degree  Brix  of  this  solution  with- 
out temperature  correction  and  then  use  a  Spencer  sucrose 
pipette.  This  is  a  pipette  so  graduated  that  if  filled  to  the 
mark  corresponding  with  the  observed,  i.e.  the  uncorrected 
degrees  Brix,  it  will  deliver  twice  the  normal  weight  of  the 
liquid.  If  the  normal  sugar-weight  used  is  26.048  grams, 
then  52.096  grams  of  solution  will  be  delivered— if  26.000 
grams  is  the  normal  sugar-weight  employed,  then  52.000 
grams  of  solution  must  be  delivered.  The  range  of  density 
for  which  these  sucrose  pipettes  are  graduated  is  usually 
from  5°  to  25°  Brix.  Discharge  the  contents  of  this  pipette 
into  a  100  c.c.  flask,  clarify  with  basic  lead  acetate  solution, 
using  from  3  to  5  c.c.  of  this  reagent,  make  the  volume  up 
to  100  c.c.  with  water,  mix  well,  filter  and  polarize. 

D  .          Sucrose  X 100 

Purity.  Real  purity  = 


Apparent  purity 


Dry  Substance 

Polarization  X 100 
Degrees  Brix 


Sucrose  in  Condensation,  Boiler-feed  and  Waste  Water. 
The  zero  point  of  the  polariscope  must  be  accurately 
determined  by  means  of  the  400  m.m.  tube  filled  with  dis- 
tilled, or  at  least  with  optically  inactive  water.  The  limit 
of  accuracy  of  the  average  saccharimeter  may  be  taken 
as  ±.05°  Ventzke  or  possibly  even  as  ±0.10°  Ventzke,  and 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    65 


this  limitation  must  be  borne  in  mind  in  accepting  the 
findings  of  such  polarimetric  determinations. 

A  sample  of  condensation- water,  for  instance,  is  examined 
as  follows :  Note  the  degree  Brix  of  the  solution.  Measure 
out  100  c.c.,  if  need  be,  clarify  with  basic  lead  acetate  solution 
or  with  alumina  cream,  dilute  up  to  110  c.c.,  shake  well,  filter 
and  polarize.  Increase  the  reading  by  T\,  divide  the  cor- 
rected reading  by  2,  as  the  400  m.m.  tube  has  been  used. 
Take  the  figure  in  the  Schmitz  table  under  the  degrees 
Brix  nearest  that  observed — the  column  headed  "  Per  cent 
Sucrose  "  in  the  table  then  shows  the  value  sought. 

Example. 

Degree  Brix  of  solution  =0.54 

Polariscope  reading  observed  in  400  m.m.  tube  =  0.20 
Corrected  pol.  reading  (+TV)  =0.22 

Divide  this  by  2  as  400  m.m.  tube  was  used        =0.11 

Consult  Schmitz's  Table. 


Degree  Brix  from  0.5  to  12.0. 

Tenths  of  Polari- 
scope Degrees. 

Per  Cent 
Sucrose. 

0.1 

0.03 

0.2 

0.06 

0.3 

0.08 

0.4 

0.11 

0.5 

0.14 

0.6 

0.17 

0.7 

0.19 

0.8 

0.22 

0.9 

0.25 

As  will  be  seen,  the  polariscopic  reading  in  the  Schmitz 
table,  nearest  to  0.11  is  0.1,  and  this  corresponds  to  0.03% 
sucrose;  this  therefore  is  the  percentage  amount  of  sucrose 
in  the  condensation  water  examined. 


66  SUGAR  ANALYSIS 

If  preferred,  the  sucrose  in  condensation  and  other 
waters  can  also  be  determined  as  invert  sugar. 

Possible  Sources  of  Error  in  Polarization.  In  all 
determinations  of  sucrose  by  the  saccharimeter,  there  are 
numerous  sources  of  error  which  must  be  guarded  against 
most  carefully.  These  shall  now  be  briefly  referred  to. 

1.  As  already  mentioned,  the  sample  must  be  permitted 
to  acquire  the  temperature  of  the  room  in  its  closed  receptacle 
before  it  is  taken  out  immediately  before  analysis.     This 
is  done  to  guard  against  its  drying  out,  which  would  entail 
too  high  a  polarization,  or,  on  the   other  hand,  to  prevent 
a  condensation  of  moisture  on  the  sample  if  the  latter  be 
colder  than  the  room  in  which  it  is  to  be  analyzed.     For  the 
same  reasons  all  mixing  of  the  sample  and  its  weighing, 
must  be  done  as  quickly  as  possible. 

Concentration  of  the  sugar  solution  during  nitration 
must  be  avoided  by  keeping  both  funnel  and  receiving  flask, 
or  beaker,  covered  during  the  operation. 

2.  The  polariscope  must  be  set  up  in  a  place  as  free  as 
possible     from    all    jar    and    vibration    of    machinery.     A 
thick  plate  of  soft  rubber  placed  beneath  the  instrument 
is  helpful  to  this  end. 

The  saccharimeter  must  be  in  a  dark  room,  free  from 
all  interfering  lights,  yet  the  air  must  be  allowed  to  circulate 
freely  around  it  and  the  temperature  must  be  kept  as  even 
as  possible  in  the  polariscope  booth. 

3.  Polarizations  must  be  made  only  on  solutions  which 
are  perfectly  clear  and  limpid  and  which  show  a  perfectly 
circular  field  in  the  instrument.     The  scale-reading  must  be 
taken  only  when  the  halves  of  the  circular  field  are  of  equal 
intensity  to  the  eye  of  the  observer. 

4.  An  excess  of  subacetate  of  lead  must  be  avoided  in 
clarification.     The  100°  mark  on  a  saccharimeter  is  deter- 
mined by  a  length  of  200  m.m.  of  a  standard  sugar  solution 
obtained  by  dissolving  the  normal  weight  of  pure  sucrose 
in  pure  water  and  bringing  the  volume  up  to  100  cubic 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    67 

centimeters  at  some  given  standard  temperature,  20°  C. 
is  prescribed  by  the  International  Commission. 

Any  precipitate  occupying  a  part  of  this  space  of  100 
cubic  centimeters  which  should  be  filled  by  the  solution, 
naturally  causes  the  solution  to  be  too  concentrated  and 
therefore  results  in  polarizations  that  are  too  high.* 

If  account  is  to  be  taken  of  this  error  and  the  same 
allowed  for,  use  can  be  made  of  the  double  dilution  method, 
due  to  Scheibler,  and  which  is  as  follows: 

The  normal  weight  of  sugar  is  dissolved  in  distilled  water; 
a  measured  amount  of  subacetate  of  lead  solution  is  added, 
the  volume  is  made  up  to  100  c.c.  and  the  solution  filtered 
and  polarized. 

A  second  solution  is  prepared  in  the  same  manner, 
except  that  its  volume  is  made  double  the  volume  of  the 
former  solution,  that  is  to  say  to  a  volume  of  200  c.c.; 
this  solution  is  then  also  filtered  and  polarized. 

Assuming  that  the  volume  of  the  lead  precipitate  formed 
is  identical  in  both  cases,  it  is  evident  that  the  polarization 
of  the  more  dilute  solution  must  be  somewhat  less  than 
one  half  the  polarization  of  the  more  concentrated  solution. 

The  corrected  polarization  is  then  found  as  shown  in 
the  following  example: 

Polarization  of  1st  solution  (100  c.c.  in  volume)  =9.6.80 
2d        "        (200  c.c.  in  volume)  =48.25 
48.25  X  2  =  96.50 

96.80-96.50=  0.30X2  =  0.60  and, 
96.80-0.60  =  96.20  the   corrected  polarization. 

Or,  expressed  more  briefly, 

corrected    polarization  =  (48.25X4)  -96.80  =  96.20. 

To  correct  the  errors  of  Scheibler's  method  Sachs  washes 
the  precipitate  obtained  in  clarification  with  hot  and  cold 

*Wiechmann,  School  of  Mines  Quarterly,  Columbia  University, 
Vol.  XXV. 


68  SUGAK  ANALYSIS 

water  until  all  sugar  has  been  removed.  This  precipitate 
is  then  placed  in  a  100  c.c.  flask,  a  half  normal  weight  of 
sucrose  is  added  and  the  volume,  after  complete  solution 
has  been  effected,  is  made  up  to  100  c.c.  After  filtration, 
the  polarization  is  made  in  a  400  m.m.  tube. 
Let  P  =  true  polarization  of  the  sucrose  used, 

P'  =  polarization  of  sucrose  plus  the  precipitate, 
then  the  volume  of  the  precipitate  is  obtained  by  the 
formula 

IQO(P'-P) 

and  the  correct  polarization  where  the  volume  of  solution  = 
100  c.c.  is  found  by  the  formula: 


100 


Example.  Polarization  of  normal  weight  of  a  sugar, 
made  up  to  100  c.c.  solution,  =  95.0° 
Ventzke.  Volume  of  precipitate  formed 


the  correct  polarization  of  the  sugar  will  be: 
(100X95.0)  -(0.5X95.0) 

~ 


Wiechmann  *  dries  the  washed  precipitate  and  from 
its  weight  and  specific  gravity  calculates  its  volume  by  the 
formula: 

w 

v  =  - 
sp.gr. 

and  then  determines  the  correct  oolarization  by  use  of  the 
formula  above  given. 

*  Proc.  Fifth  Int.  Cong.  Applied  Chemistry,  1904. 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    69 

A  convenient  and  practical  method  of  obviating  the 
precipitate-volume  error  has  been  devised  by  Home.*  His 
description  follows. 

"  The  normal  weight  of  sugar  is  dissolved  in  water 
in  a  100  c.c.  flask  and  made  up  to  the  mark  without  defeca- 
tion. The  concentration  is  thus  at  exactly  the  proper  degree. 
It  now  remains  to  defecate  the  solution  properly  by  pre- 
cipitating the  impurities  in  such  a  way  as  to  produce  the 
minimum  change  in  the  concentration  of  the  solution  of 
sucrose.  This  is  accomplished  by  adding  to  the  100  c.c. 
of  liquid  small  quantities  of  powdered  anhydrous  lead 
subacetate  until  the  impurities  are  nearly  all  precipitated. 
This  point  is  as  easily  determined  as  in  the  defecation  by  a 
solution  of  the  same  salt.  The  organic  and  mineral-acid 
radicals  in  the  solution  combine  with  and  precipitate  the 
lead  and  lead  oxide  of  the  dry  salt,  while  the  acetic-acid 
radical  of  the  lead  subacetate  passes  into  solution  to  com- 
bine with  the  bases  originally  united  to  the  other  acid 
radicals." 

5.  The  quartz  control  plates  must  be  mounted  in  such  a 
manner  that  they  shall   be  absolutely  under  no  pressure 
or  strain,  as  otherwise  they  incur  marked  changes  in  their 
optical  value,  f 

6.  The  cover  glasses  of  the  polariscope  tubes  must  be 
optically  inactive  and  put  under  no  strain  by  the  cover- 
caps.     Bayonet  cover-caps  are  preferable  for  this  purpose 
to  the  screw-caps  in  general  use. 

7.  As  changes  in  temperature  affect  both   the  optical 
rotation  value  of  sugar  solutions    and  of   the  polariscope, 
accurate  readings  can  only  be  secured  when: 

1st.  The  polariscope  is  at  the  temperature  at  which  it 
was  graduated; 


*  J.  Am.  Chem.  Soc.,  Vol.  XXVI,  p.  186. 

f  Wiechmann :    School  of  Mines  Quarterly,  Columbia  University, 
Vol.  XX. 


70  SUGAR  ANALYSIS 

2d.  The  sugar  solution  of  the  normal  weight  of  sugar, 
is  made  up  to  100  c.c.  at  that  same  temperature; 

3d.  Is  polarized  at  that  same  temperature. 

The  International  Commission  for  Uniform  Methods 
of  Sugar  Analysis  accepted  20°  C.  as  the  standard  tem- 
perature, and  therefore,  in  conformity  with  the  directions 
of  that  Commission,  the  saccharimeter  must  be  graduated 
at  20°  C.,  the  sugar  solution  must  be  made  up  at  20°  C. 
and  must  be  polarized  at  20°  C. 

The  Commission  however  also  authorized  that,  "  for 
those  countries,  the  temperature  of  which  is  generally 
higher,  it  is  permissible  that  the  saccharimeters  (polariscopes) 
be  adjusted  at  30°  C.,  or  any  other  suitable  temperature, 
under  the  conditions  specified  above,  and  providing  that 
the  analyses  of  sugar  be  made  at  that  same  temper- 
ature." * 

7.  The  source  of  light  must  be  carefully  adjusted  so 
that  an  absolutely  uniform  and  sufficiently  intensive  illu- 
mination of  the  polariscopic  field  is  insured.  It  should  more- 
over be  placed  at  a  distance  sufficiently  far  from  the  instru- 
ment to  prevent  any  heating  of  the  latter.  White  light 
such  as  emanates  from  a  Welsbach  burner  or  from  an 
electric  incandescent  bulb,  must  never  be  used  unless, 
before  entering  the  polariscope,  it  is  made  to  pass  through 
a  layer  1.5  cm.  thick  of  a  6%  aqueous  solution  of  potassium 
dicjiromate. 

B.  Determination  of  Sucrose,  in  the  Presence  of  Other 
Optically  Active  Substances.  The  determination  of  sucrose 
by  the  method  now  to  be  described  is  based  on  the  fact  that 
sucrose  is  changed  by  the  action  of  acid  from  a  dextro- 
rotatory substance  into  a  levo-rotatory  mixture  of  dextrose 
and  levulose.  The  method  is  particularly  applicable  when 

*  In  this  connection  see  also:  C.  A.  Browne,  Seventh  International 
Congress  of  Applied  Chemistry,  Vol.  XIX. 

Home,  Journal  of  Industrial  and  Engineering  Chemistry,  1912, 
p.  41. 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    71 

dextrose  or  starch  sugar,  considerable  amounts  of  invert 
sugar,  or  when  raffinose  is  present  together  with  the 
sucrose. 

This  method  is  known  as  Clerget's  method,  but  it 
has  received  some  modifications  by  other  investigators. 
According  to  Herzfeld's  modification  it  is  carried  out  as 
follows : 

Clerget-Herzfeld  Method.*  Weigh  out  26.00  grams  of 
the  sample,  and  determine  the  polarization  as  usual  at 
20°  C.  Of  the  solution,  take  50  c.c.  for  inversion,  or  weigh 
out  separately  13.00  grams  of  the  sample.  Dissolve  with 
about  75  c.c.  of  water  in  a  100  c.c.  flask;  add,  after  complete 
solution  has  been  effected,  5  c.c.  hydrochloric  acid  (sp.gr. 
1.188),  containing  38  per  cent  HC1.  Heat  quickly,  in  two  or 
three  minutes,  on  a  water-bath  up  to  between  67°  and 
70°  C.  Then  keep  the  temperature  of  the  solution  for 
five  minutes  as  close  to  69°  C.  as  possible.  Agitate  con- 
stantly. Then  cool  quickly  to  20°  C.,  fill  with  distilled 
water  up  to  the  100  c.c.  mark,  and  polarize  in  a  tube  provided 
with  an  accurate  thermometer.  The  temperature  at  which 
the  reading  is  taken  should  be  20°  C.  and  the  temperature 
of  the  saccharimeter  must  also  be  20°  C. 

The  use  of  subacetate  of  lead  for  clarifying  purposes  is 
not  permissible  as  this  reagent  affects  the  rotatory  power 
of  invert  sugar.  If  a  decolorant  must  be  used,  a  little, 
specially  prepared  blood-carbon  should  be  employed. 

The  result  is  calculated  as  follows : 

Let  R  =  sucrose, 

$  =  sum  of  the  two  polarizations  before  and  after 

inversion,  the  minus  sign  being  ignored, 
t  =  degrees   Centigrade   at   which   the    polarization 
after  inversion  was  observed, 

*  For  use  of  invertase  as  hydrolyst  see  International  Sugar  Journal, 
1911;  p.  145.  For  use  of  hydrochloric  acid  and  urea  for  determining 
sucrose  in  cane  molasses,  ibid.,  p.  206. 


72  SUGAR  ANALYSIS 

then, 

R: 


142.66 -(0.5X0 

The  two  polarizations — the  one  before,  the  other  after 
inversion,  must  always  be  made  at  one  and  the  same  tem- 
perature, because  the  optical  rotation  value  of  invert  sugar 
is  materially  influenced  by  temperature  changes.  As  the 
International  Commission  has  accepted  20°  C.  as  the  stand- 
ard temperature,  20°  C.  is  used  in  the  above  formula 

R  100XS 


142.66 -(0.5X20) 
which,  of  course,  is  equivalent  to: 

100X3 
132.66 

As    100-7-132.66  =  0.7538,    the    formula   may   be   given  its 
simplest  expression  thus: 

#  =  0.7538X3 

It  is  best  to  carry  out  both  determinations  at  20°  C.  if 
possible.  If,  however,  the  determinations  are  made  at  any 
other  temperature  between  10°  C.  and  30°  C.,  Table  X  gives 
a  series  of  factors  by  which  it  is  necessary  to  multiply  the 
sum  of  the  indications,  before  and  after  inversion. 

Example.     Direct  polarization,  86.0  at  22°  C. 

Polarization    of    half    normal    weight    after 
inversion— 12.5  at  22°  C.— 12.5X2  =  25.0 
86.0+25.0  =  111.0. 

*  The  value  142.66  in  this  formula  is  based  on  the  fact  that  a  pure 
normal  weight  sugar  solution  which  polarizes  100°  Ventzke  at  0°  C. 
in  a  200  m.m.  tube,  polarizes,  after  complete  inversion— 42.66°  so  that 
the  entire  decrease  in  rotation  at  0°  C.  =  142.66.  Account  must  be 
taken  of  the  fact  that  the  rotatory  value  of  invert  sugar  decreases  0.5° 
for  each  1°  C.  temperature  elevation  above  0°  C. 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    73 


Referring  to  Table  X,  opposite  to  22°  C.  there  will  be 
found  the  factor  0.7595.  Multiplying  111 X. 7595  =  84.3; 
this  is  the  desired  result. 

If  any  other  weight  than  13.00°  grams  is  used  for  the 

lOOSf 
determination,  the  value  142.66  in  the  formula R  =  ~Anf. 

142.66— \t 

does  not  give  correct  results,  because  the  specific  rotatory 
power  of  an  invert  sugar  solution  varies  with  the  degree 
of  concentration  of  the  solution. 

The  following  table  shows  the  value  that  under  the 
circumstances,  must  be  used  in  its  stead. 


Grams  of 

Sucrose  in 
100  c.c. 


Use 
Factor. 


1 141.85 

2 141.91 

3 141.98 

4 142.05 

5 142.12 

6 142.18 

7 142.25 

8 142.32 

9 142.39 

10  142.46 


Use 
Factor. 


Grams  of 

Sucrose  in 

100  c.c. 

11 142.52 

12 142.59 

13 142.66 

14 142.73 

15 142.79 

16 142.86 

17 142.93 

18 143.00 

19 143.07 

20  143.13 


If  no  other  optically  active  body  is  present  besides  the 
sucrose,  the  Clerget  polarization  will  of  course  return  a 
value  equivalent  to  the  direct  polarization  value  originally 
found. 

Example.     Polarization  of  normal  weight  before  inver- 
sion, 87.5,  at  20°  C. 

Polarization    of   half    normal    weight    after 
inversion,  - 14.3  at  20°  C. 


-14.3X2 
-28.6 


R  = 


100X116.1 
142.66-10 

11610 


74  SUGAR  ANALYSIS 

Sucrose  and  Invert  sugar.  The  following  case  is  a  so- 
-called  invert  sugar  syrup,  essentially  a  mixture  of  sucrose 
and  invert  sugar. 

Direct  polarization  at  20°  C.  =  +15.0° 

Polarization  of  half  normal  weight  after  inversion  at 
20°  C=-13.0° 

-13.0X2  =-26.0,  hence: 

S  =  15.0+26.0  =  41.0 
and 

R  =  0.7538  X41  =  30.90%. 

That  is  to  say  this  mixture  contains  30.90%  of  sucrose. 
Sucrose  and  Dextrose.     In  this  instance  some  glucose 
syrup  had  been  mixed  with  cane  syrup. 

Direct  polarization,  at  20°  C.  =  +72.0 

Polarization  of  half  normal  weight  after  inversion  at 
20°C.  =  +9.0 

+9X2  =  18.0 

Hence  S  =  72  - 18.0  =  54.0 

R  =  0.7538  X  54  =  40.70% 

Hence  this  mixture  contains  40.70%  sucrose. 

Sucrose  and  Commercial  Glucose  mixtures  can  be 
analyzed  optically  by  using  the  method  of  hot  polarization 
due  to  Chandler  and  Ricketts.* 

*  Abstracted  from  Second  Annual  Report  of  the  State  Board  of 
Health  of  New  York,  1882, 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    75 

This  method  depends  upon  the  following  well-known 
facts : 

1.  Dextrose,  under  the  conditions  of  analysis,  exerts  a 
constant  effect  upon  the  plane  of  polarized  light  at  all 
temperatures  under  100°  C. 

2.  Levulose.     The   action   of   levulose   is   not   constant, 
the  amount  of  rotation  to  the  left  being  diminished  as 
the  temperature  is  increased. 

3.  Invert  sugar,  being  a  mixture  of  one  half  dextrose 
and  one  half  levulose,  does  not  affect  the  plane  of  polarized 
light   at  a  certain  temperature,   somewhere   near  87°   C. 
(for  it  can  easily  be  seen  that  the  constant  dextro-rotatory 
power   of   dextrose   must   be   neutralized   by   the   varying 
levo-rotatory  power  of  levulose  at  some  such  temperature. 
The  exact  temperature  is  determined  by  experiment). 

4.  Cane  sugar,  when  acted  on  by  dilute  acids,  is  con- 
verted into  invert  sugar,  while  dextrose  remains  practically 
unaltered. 

Hence,  if  a  "  mixed  sugar  "  is  heated  with  dilute  acids, 
the  cane  sugar  present  is  converted  into  invert  sugar, 
which,  with  that  originally  present  due  to  the  process  of 
manufacture,  is  optically  inactive  at  a  certain  temperature 
(near  87°  C.);  while  the  commercial  glucose  added,  pre- 
serving its  specific  rotatory  effect,  will  at  this  temperature 
show  a  deviation  to  the  right  in  proportion  to  the  amount 
present  and  according  to  its  nature. 

It  is  only  necessary,  therefore,  to  secure  some  means 
of  heating  the  observation  tube  of  the  ordinary  polariscope, 
so  that  readings  may  be  taken  at  any  temperature  under 
100°  C.  The  middle  section  of  a  saccharimeter  ordinarily 
intended  for  the  observation  tube  alone,  is  so  modified  as 
to  admit  of  the  interposition  of  a  metallic  water-bath, 
provided  at  the  ends  with  metal  caps,  which  contain  circular 
pieces  of  clear  plate-glass.  The  tube  for  holding  the  sugar 
solution  to  be  polarized,  is  provided  with  a  tubule  for  the 
insertion  of  a  thermometer  in  the  sugar  solution.  The 


76  SUGAE  ANALYSIS 

metallic  caps  at  the  end  of  the  tube  rest  on  projecting 
shelves  inside  the  water-bath,  thus  bringing  the  tube  into 
the  center  of  the  bath,  where  it  is  completely  surrounded 
by  water.  The  cover  of  the  water-bath  is  arranged  for  the 
insertion  of  a  thermometer,  so  that  the  temperatures  of  the 
water-bath  and  of  the  sugar  solution  may  both  be  ascer- 
tained. The  water-bath  is  heated  by  spirit-lamps,  gas- 
burners  or  some  other  heating  device.  By  experiment 
it  has  been  found  that  about  87°  C.  is  the  temperature 
at  which  the  reading  of  a  pure  inverted  sugar  solution  is 
zero  on  the  sugar  scale. 

In  working  out  this  method  it  was  next  found  necessary 
to  determine  the  value  of  a  degree  of  the  scale  in  terms  of 
the  glucose  known  to  be  the  variety  used  to  adulterate  cane 
sugar.  It  was  found  that  the  rotation  to  the  right  at  86°  C. 
was  41°,  when  using  a  solution  containing  in  100  c.c.  fifteen 
grams  of  a  sample  containing  85.476  per  cent  chemically 
pure  glucose.  Hence  as  fifteen  grams  was  the  amount  taken, 
15X*!£J£-^4lxiOO  =  31.2717  grams,  which  represents  the 
amount  of  chemically  pure  glucose  necessary  to  read  one 
hundred  divisions  on  the  sugar  scale  of  the  instrument 
used;  or,  each  division  =  0.312717  grams  chemically  pure 
glucose.  (A  duplicate  determination  made,  by  using 
26.048  grams,  gave  as  a  factor  0.312488.) 

The  success  of  the  process  depends  greatly  upon  the 
care  exercised  in  preparing  the  sugar  solution  for  the  polari- 
scope.  The  inversion  and  subsequent  clarification  were 
accomplished  as  follows: 

26.048  grams  of  the  sugar  to  be  examined  were  com- 
pletely dissolved  in  about  75  c.c.  of  cold  water,  and  were 
treated  with  3  c.c.  of  dilute  sulphuric  acid  (1  to  5  by  volume) 
on  a  water-bath  at  a  temperature  of  about  70°  C.  for  thirty 
minutes.  The  solution  thus  inverted  was  then  rapidly 
cooled,  nearly  neutralized  with  sodium  carbonate  solution 
(saturated),  transferred  to  a  100  c.c.  flask,  and  the  gummy 
matters,  etc.,  precipitated  with  5  c.c.  of  a  solution  of  basic 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    77 

lead  acetate.  The  flask  was  then  filled  to  the  mark,  the 
solution  transferred  to  a  small  beaker,  mixed  with  enough 
bone-black  to  clarify  completely,  and  then  thrown  on  a 
fluted  filter.  The  amount  of  bone-black  necessary  to  effect 
decolorization  depends  on  the  grade  of  the  sugar  and  on  the 
color  of  the  solution.  It  was  not  found  necessary  to  use, 
even  with  sugars  of  the  lowest  grade,  more  than  five  grams. 

The  clarified  inverted  sugar  solution  was  then  placed 
in  the  polarization  tube,  the  water-bath  was  filled  with 
cold  water,  the  thermometers  were  adjusted,  and  the  tem- 
perature gradually  raised  to  86°  C.  This  part  of  the  opera- 
tion should  take  about  thirty  minutes.  If  the  sample  is 
not  adulterated,  the  polariscope  reading  will  be  zero  at  86° 
C.,  while  if  glucose  is  present  the  amount  of  deviation  to 
the  right,  in  degrees  and  fractions,  multiplied  by  the  proper 
factor  and  divided  by  the  amount  taken,  will  give  the  per- 
centage of  glucose  added  as  an  adulterant. 

The  specific  rotation  of  commercial  glucose  varies  from 
about  +100  to  +125  for  the  liquid  product.  The  value 
[«]£>+ 108  is  however  generally  employed. 

In  using  this  method  it  is  however  very  important  not 
to  overlook  the  fact  that  the  liquid  which  is  made,  say  at 
20°  C.  and  polarized  at  say  87°  C.,  expands  considerably 
and  that  therefore  a  correction  must  be  made  to  allow  for 
the  dilution  due  to  such  expansion.  100  c.c.  of  water  at 
20°  C.  expand  to  103.15  c.c.  at  87°  C.  and  therefore  the 
factor  1.0315  must  be  used  for  multiplying  the  polariza- 
tion observed  at  87°  C.  to  effect  this  needed  correction.* 

An  additional  difficulty  in  using  this  method  lies  in  the 
fact  that  it  is  not  possible  to  get  as  clear  and  accurate  read- 
ings on  solutions  at  high  temperatures  as  at  20°  C.,  owing 
to  the  fact,  as  determined  by  Browne,  that  striations  are 
very  apt  to  occur  in  the  solution  under  such  observation, 

*  C.  A.  Browne,  Bureau  of  Chemistry,  Bulletin  No.  110,  Washing- 
ton, 1908. 


78  SUGAR  ANALYSIS 

unless  the  same  is  of  an  absolutely  uniform  temperature 
throughout. 

Sucrose  and  Levulose  solutions  can  also  be  analysed  in 
a  similar  manner.  Wiley  *  has  shown  that  1  gram  of  levulose 
in  -100  c.c.  of  solution  shows  a  variation  of  0.0357°  V.  for 
each  degree  Centigrade. 

To  express  this  in  a  formula: 

Let 

F  =  grams  of  levulose  in  100  c.c.  of  solution 
P'  =  degrees  Ventzke  at  high  temperature  i* 
P—      "  low  temperature  t 


F= 


0.0357(^-0 

which  means,  that  the  difference  between  the  direct  polariza- 
tion of  a  sucrose-levulose  solution  at  87°  C.  and  at  20°  C., 
for  instance,  divided  by  0.0357  (87°-20°)  gives  the  grams 
of  levulose  in  100  c.c.  of  a  solution  so  examined. 

Sucrose  and  Raffinose.  The  analytical  details  of  the 
Clerget  method  to  be  followed,  when  dealing  with  mixtures 
of  sucrose  and  raffinose,  are  precisely  as  previously  given, 
however  a  different  formula  must  be  used  in  calculating  the 
results,  because  the  dextro-rotation  of  the  raffinose  is  also 
affected  by  the  inversion  brought  about  by  the  use  of  the 
acid. 

The  specific  rotation  of  raffinose  decreases  during  the 
inversion  from  +104.5  to  +53.5 

Using  metric  cubic  centimeters,  the  normal  weight  for 
the  raffinose  hydrate  is  16.545  grams,  and  14.037  grams  for 
the  anhydride. 

These  amounts  of  raffinose  show  before  inversion  a 
polarization  of  +100°  V.,  after  hydrolysis,  a  decrease  of 
48.76°  Ventzke,  i.e.  after  hydrolysis  they  show  a  polariza- 
tion of  +51.24°  V.  at  20°  C. 

*  Principles  and  Practice  of  Agricultural  Analysis,  1897,  Vol.  Ill, 
p.  267. 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    79 

Herzfeld's  modification  of  Creydt's  formulae,  which  were 
based  on  the  old  Clerget  process,  are  at  present  generally 
used. 

Let  the  normal  weight  (26.00  grams)  of  a  sample  consist- 
ing of  S%  sucrose  and  R%  raffinose  anhydride  be  dissolved 
to  100  metric  c.c.  at  20°  C.  and  polarized  at  20°  C. 

The  polarization  of  the  sucrose  will  be  represented  by 
S,  that  of  the  raffinose  by : 

26.000 


14.037 


=  1.852 


in  other  words,  this  1.852  is  the  ratio  of  the  normal  weight 
of  raffinose  anhydride  to  that  of  sucrose.  Let  the  sum  of 
the  direct  polarizations  of  the  sucrose  and  raffinose  =  P 

Then: 

P  =  S+  1.852  R 

~ 

~ 


1.852 


Inversion  having  been  effected,  let  P'  represent  the  sum 
of  the  sucrose  and  raffinose  invert  polarizations,  then 

P'=-0.3266S+0.9490#. 
0.3266P+P' 


R  = 


1.554 
0.5124P-P' 


0.839 

Example.     Direct  Pol.  =     51.0 

Pol.  after  inversion    =  —  12.5 


80  SUGAR  ANALYSIS 

This  sample  therefore  contains 

Sucrose    =46.04% 
Raffinose  =   2.67% 

If  the  observation  of  the  inverted  raffinose  solution 
has  not  been  made  at  20°  C.  a  correction  of  0.0038°  for 
each  degree  Centigrade  above  or  below  20°  C.  must  be 
introduced.  This  correction  is  effected  by  the  formula.* 

Polarization    j          f    Polarization     1 
after  inversion   |   =   j   after  inversion   [  +0.0038£(20— t), 
at20°C.      J         I        aU°C.        J 

in  which  S  reoresents  the  sum  of  the  polarizations  before  and 
after  inversion. 

Example.     Suppose  a  solution  of  sucrose  and  raffinose 

polarized : 

Before  inversion,  105.0°; 
After  inversion,  — 22.0°  at  a  temperature  of 

18.2°  C. 

Then  the  polarization  after  inversion  at  20°  C.  will  be 
equal  to: 

-22.0+0.0038(105.0+22.0)  (20.0 -18.2) 

-22.0+0.0038(+127.0)(+1.8) 
-22.0+0.86868 

=  -21.13 

The  following  table  by  Hammerschmidt  f  permits  the 
ready  determination  of  the  value  0.0038$(20— t)  occurring 
in  above  formula,  and  proves  of  great  convenience  where 
many  calculations  of  this  kind  are  called  for. 

*Zeitschrift  des  Vereines  fur  Rubenzucker-Industrie,  Vol.  XL, 
p.  201. 

t  Correspondenz-blatt  des  Vereins  Akademischgebildeter  Zucker 
techniker,  Vol.  I,  No.  3. 


SUCROSE  DETERMINATION  BY  OPTICAL  ANALYSIS    81 


0- 

134 

132 

130 

128 

126 

124 

122 

120 

20-*  =  1 

0.51 

0.50 

0.49 

0.49 

0.48 

0.47 

0.46 

0.46 

2 

1.02 

1.00 

0.99 

0.97 

0.96 

0.94 

0.93 

0.91 

3 

1.53 

1.50 

1.48 

1.46 

1.44 

1.41 

1.39 

1.37 

4 

2.04 

2.01 

1.98 

1.95 

1.92 

1.88 

1.85 

1.82 

5 

2.55 

2.51 

2.47 

2.43 

2.39 

2.36 

2.32 

2.28 

6 

3.06 

3.01 

2.96 

2.92 

2.87 

2.83 

2.78 

2.74 

7 

3.56 

3.51 

3.46 

3.40 

3.35 

3.30 

3.25 

3.19 

8 

4.07 

4.01 

3.95 

3.89 

3.83 

3.77 

3.71 

3.65 

9 

4.58 

4.51 

4.45 

4.38 

4.31 

4.24 

4.17 

4.10 

S- 

118 

116 

114 

112 

110 

105 

100 

95 

20-*  =  1 

0.45 

0.44 

0.43 

0.43 

0.42 

0.40 

0.38 

0.36 

2 

0.90 

0.88 

0.87 

0.85 

0.84 

0.80 

0.76 

0.72 

3 

1.35 

1.32 

1.30 

1.28 

1.25 

1.20 

1.14 

1.08 

4 

1.79 

1.76 

1.73 

1.70 

1.67 

1.60 

1.52 

1.44 

5 

2.24 

2.20 

2.17 

2.13 

2.09 

2.00 

1.90 

1.81 

6 

2.69 

2.64 

2.60 

2.55 

2.51 

2.39 

2.28 

2.17 

7 

3.14 

3.09 

3.03 

2.98 

2.93 

2.79 

2.66 

2.53 

8 

3.59 

3.53 

3.47 

3.40 

3.34 

3.19 

3.04 

2.89 

9 

4.04 

3.97 

3.90 

3.83 

3.76 

3.59 

3.42 

3.25 

S  = 

90 

85 

80 

75 

70 

65 

60 

55 

50 

2Q-t  =  l 

0.34 

0.32 

0.30 

0.29 

0.27 

0.25 

0.23 

0.21 

0.19 

2 

0.68 

0.65 

0.61 

0.57 

0.53 

0.49 

0.46 

0.42 

0.38 

3 

1.03 

0.97 

0.91 

0.86 

O.SO 

0.74 

0.68 

0.63 

0.57 

4 

1.37 

1.29 

1.22 

1.14 

1.06 

0.99 

0.91 

0.84 

0.76 

5 

1.71 

1.62 

1.52 

1.43 

1.33 

1.24 

1.14 

1.05 

0.95 

6 

2.05 

1.94 

1.82 

1.71 

1.60 

1.48 

1.37 

1.25 

1.14 

7 

2.39 

2.26 

2.13 

2.00 

1.86 

1.73 

1.60 

1.46 

1.33 

8 

2.74 

2.58 

2.43 

2.28 

2.13 

1.98 

1.82 

1.67 

1.52 

9 

3.08 

2.91 

2.74 

2.57 

2.39 

2.22 

2.05 

1.88 

1.71 

0- 

45 

40 

35 

30 

25 

20 

15 

10 

5 

2Q-t  =  l 

0.17 

0.15 

0.13 

0.11 

0.10 

0.08 

0.06 

0.04 

0.02 

2 

0.34  0.30 

0.27 

0.23 

0.19 

0.15 

0.11 

0.08 

0.04 

3 

0.51 

0.46 

0.40 

0.34 

0.29 

0.23 

0.17 

0.11 

0.06 

4 

0.68 

0.61 

0.53 

0.46 

0.38 

0.30 

0.23 

0.15 

0.08 

5 

0.86 

0.76 

0.67 

0.57 

0.48 

0.38 

0.29 

0.19 

0.10 

6 

1.03 

0.91 

0.80 

0.68 

0.57 

0.46 

0.34 

0.23 

0.11 

7 

1.20 

1.06 

0.93 

0.80 

0.67 

0.53 

0.40 

0.27 

0.13 

8 

1.37 

1.22 

1.06 

0.91 

0.76 

0.61 

0.46 

0.30 

0.15 

9 

1.54 

1.37 

1.20  1.03 

0.86 

0.68 

0.51 

0.34 

0.17 

CHAPTER  V 
SUCROSE  DETERMINATION  BY  CHEMICAL  ANALYSIS 

Qualitative  Test  for  Sucrose.  A  delicate  test  for  the 
presence  of  sucrose  is  afforded  by  the  use  of  a-naphthol. 

Place  2  c.c.  of  the  solution  to  be  examined  in  a  test- 
tube.  Add  2  drops  of  a  10%  solution  of  a-naphthol  in 
alcohol.  Then  allow  about  5  c.c.  of  concentrated  sulphuric 
acid  to  flow  down  the  side  of  the  test-tube  and  settle  at  the 
bottom. 

If  any  appreciable  quantity  of  sucrose  is  present  a  violet 
color  zone  will  appear  at  the  line  of  contact  of  the  two 
liquids.  This  color  is  caused  by  reaction  products  between 
the  decomposition  products  of  the  sugar  and  of  the  phenol 
derivatives. 

As  nitric  acid  interferes  with  the  reaction  care  must 
be  used  that  this  is  not  present.  Ammonia,  lime  salts  and 
most  organic  impurities  found  in  water  do  not  disturb  the 
test.  Solutions  of  invert  sugar  however  also  give  the 
violet  color  reaction  and  this  must  be  borne  m  mind  in 
interpreting  the  test. 

As  there  is  no  absolutely  distinctive  chemical  test  for 
sucrose,  it  is  best  to  transform  the  sucrose  into  a  saccharate — 
strontium  bisaccharate  for  instance — to  set  the  sucrose 
free  from  the  strontium  by  precipitating  the  same  as  car- 
bonate and  then  to  identify  the  sucrose  optically  or  other- 
wise. 

Quantitative  Determination  of  Sucrose  as  Invert  Sugar. 
This  is  effected  by  taking  advantage  of  the  fact  that  sucrose 

82 


DETERMINATION  BY  CHEMICAL  ANALYSIS       S3 

by  inversion  with  acids  or  invertase,  is  changed  into  invert 
sugar  which  reduces  alkaline  copper  solutions. 
According  to  the  reaction: 

Ci2H22Oi  i +H20  =  2C6Hi206 

L  Sucrose  Water        Invert  sugar 

95  parts  of  sucrose  yield  100  parts  of  invert  sugar  and 
therefore,  the  amount  of  invert  sugar  yielded  by  an  inverted 
sucrose  solution  multiplied  by  0.95  represents  the  amount 
of  sucrose  originally  present. 

The  solution  generally  employed  for  the  purpose  is 
a  strongly  alkaline  solution  of  sulphate  of  copper  and 
Rochelle  salts.  This  process  was  first  suggested  by  Trommer 
in  1841  and  later  has  received  much  attention  at  the  hands 
of  others,  among  them  Barreswil,  1844,  Fehling,  1848, 
Soxhlet,  1878,  and  Herzfeld  in  more  recent  years. 

The  invert  sugar  takes  away  a  part  of  the  oxygen  from 
the  cupric  oxide  and  reduces  the  same  to  cuprous  oxide 
which  latter  separates  as  a  bright  scarlet  colored  precipi- 
tate, insoluble  in  water.  The  invert  sugar  itself  is  broken 
up  into  several  compounds  among  which  oxalic  acid,  formic 
acid,  etc.,  may  be  identified  and  all  of  which  remain  in 
solution. 

It  has  been  ascertained  that  the  degree  of  reducing 
power  of  invert  sugar  is  dependent  upon  the  relative  excess 
of  the  copper  salt  present  in  the  solution  and  therefore  it 
is  necessary  in  making  such  determinations  to  adhere 
strictly  to  prescribed  condition  of  analysis. 

It  is  a  matter  of  choice  whether  one  carries  on  such 
determinations  by  gravimetric  or  by  volumetric  analysis — 
in  the  former,  the  weight  of  cuprous  oxide  produced,  or 
of  this  oxide  reduced  to  metallic  copper,  is  weighed  and 
the  amount  of  sucrose  corresponding  to  this  amount  is 
determined;  in  volumetric  analysis  the  volume  of  a  sugar 
solution  of  known  strength  which  is  required  to  complete 
the  reaction,  is  measured. 


84  SUGAR  ANALYSIS 

Fehling's  Solution.  The  Fehling  solution  now  generally 
used  in  these  determinations  is  prepared  as  follows: 

Solution  I.  Dissolve  34.639  grams  of  sulphate  of  cop- 
per, recrystallized,  CuSO4-5H2O  in  water,  making  the 
solution  up  to  500  c.c. 

Solution  II.  Dissolve  173  grams  of  pure,  crystallized 
Rochelle  salts  in  distilled  water.  To  this  solution  add  100 
c.c.  of  a  solution  of  purest  sodium  hydrate  containing 
516  grams  NaOH  per  liter,  and  make  the  volume  of  this 
mixed  solution  up  to  500  c.c. 

Solutions  I  and  II  must  be  kept  in  separate  flasks; 
immediately  before  use  mix  solutions  I  and  II  in  equal 
volumes. 

Inversion  of  Sucrose.  The  first  step  to  be  taken  in 
order  to  determine  sucrose  by  means  of  Fehling's  solution 
is  of  course  the  transformation  of  sucrose  into  invert  sugar. 
This  is  accomplished  as  follows  according  to  Herzfeld's 
directions.* 

Weigh  out  13.0  grams  of  the  sugar  sample  and  dissolve 
with  75  c.c.  distilled  water  in  a  100  c.c.  (metric)  flask. 
When  solution  has  been  completely  effected,  add  5  c.c. 
of  hydrochloric  acid,  having  a  specific  gravity  of  1.188, 
mix  thoroughly,  insert  a  thermometer  in  the  flask  and  then 
place  the  same  into  a  water-bath  which  has  a  temperature 
of  72°  to  73°  C. 

The  flask  with  its  contents  is  kept  for  5  minutes  at  a 
temperature  of  69°  C.  the  flask  being  frequently  agitated 
during  this  time.  As  it  may  take  from  two  to  five  minutes 
to  raise  the  temperature  of  the  flask's  contents  up  to  69°  C. 
the  whole  operation  may  take  from  seven  to  ten  minutes 
time — but  it  must  never  exceed  ten  minutes. 

When  the  inversion  has  been  achieved  the  flask  is  imme- 
diately immersed  in  water  having  a  temperature  of  20°  C., 

*  Originally  given  in  the  Zeitschrift  der  Deutschen  Zucker  Industrie, 
1888,  p.  699,  but  modified  to  meet  the  present  standards  of  the  Inter- 
national Commission. 


DETERMINATION  BY  CHEMICAL  ANALYSIS        85 

the  thermometer  is  cautiously  removed  from  the  solution, 
any  solution  adhering  to  the  thermometer  is  carefully 
washed  back  into  the  flask,  its  contents  neutralized  with 
sodium  hydrate  solution,  made  up  to  exactly  100  c.c.,  and 
filtered. 

The  inverted  sugar  solution  thus  prepared  is  now  ready 
for  determination  by  either  volumetric  or  gravimetric 
analysis. 

Volumetric  Analysis.  Before  using  Fehling's  solution 
it  is  necessary  that  its  reducing  value  be  exactly  determined. 
This  can  be  accomplished  as  follows: 

9.5  grams  of  perfectly  dry  chemically  pure  sucrose  or 
best  grade  of  refined  sugar  are  inverted  exactly  as  above 
described.  As  9.5  parts  of  sucrose  yield  on  inversion  10 
parts  of  invert  sugar,  the  inverted  solution  will  contain 
10.0  grams  of  invert  sugar. 

50  c.c.  of  this  solution,  containing  5.0  grams  of  invert 
sugar,  are  measured  into  a  1000  c.c.  flask,  sodium  carbonate 
is  added  until  a  bit  of  red  litmus  paper  thrown  into  it  turns 
blue,  and  then  the  contents  of  the  flask  are  made  up  to  the 
1000  c.c.  mark  with  distilled  water  and  well  mixed. 

Each  c.c.  of  this  solution  now  contains  0.005  gram  invert 
sugar. 

With  an  accurate  pipette  25  c.c.  of  Fehling's  solution  I, 
and  25  c.c.  of  Fehling's  solution  II  are  measured  into  a 
deep  porcelain  dish  or  casserole;  to  this  50  c.c.  of  distilled 
water  are  added  and  the  mixture  is  rapidly  raised  to  the 
boiling  point. 

The  inverted  sugar  solution  is  then  run  into  the  Fehling 
solution  from  a  burette,  graduated  in  rtr  c.c.,  under  constant 
stirring  and  renewed  boiling,  until  all  of  the  copper  in  the 
solution  is  precipitated  as  cuprous  oxide.  The  operator  is 
warned  of  the  approach  of  the  end  of  the  reaction  by  the 
gradual  change  in  the  color  of  the  solution;  the  blue  color 
disappears  and  the  solution  becomes  colorless. 

The  end-point  of  'the  reaction  is  however  determined  by 


86  SUGAR  ANALYSIS 

filtering  a  few  drops  of  the  solution  through  a  very  small 
paper  filter  into  a  very  dilute  solution  of  potassium  ferro- 
cyanide  (20  grams  in  1000  c.c.  water)  with  a  little  acetic 
acid  (10%  strength)  added. 

If  a  brownish-red  color  appears,  owing  to  the  formation 
of  cupric  ferrocyanide  two-tenths  c.c.  more  of  the  inverted 
sugar  solution  are  added  to  the  Fehling  solution,  the  same  is 
again  boiled  and  the  test  repeated.  This  operation  is 
repeated  until  a  few  drops  of  the  inverted  sugar  solution 
added  to  the  ferrocyanide  solution  no  longer  produce  the 
red  coloration. 

It  is  always  well  to  confirm  the  finding  by  a  duplicate  test. 

As  previously  stated,  1  c.c.  of  the  inverted  sugar  solu- 
tion used  contains  0.005  gram  invert  sugar. 

Suppose  that  49  c.c.  of  the  inverted  sugar  solution  have 
been  used  in  the  test,  then — to  effect  the  complete  reduc- 
tion of  the  50  c.c.  of  the  Fehling  solution  used,  there  were 
required:  49.0X0.005  =  0.245  gram  invert  sugar.  This  gives 
the  strength  of  the  Fehling  solution. 

The  determination  of  sucrose  in  a  given  sample  is  con- 
ducted in  precisely  the  same  manner  as  the  standardization 
above  described. 

Thus,  suppose  we  were  dealing  wdth  a  pure  sugar  solution. 
Weigh  out  13.0  grams  of  the  sample;  invert,  as  described — 
under  exact  adherence  to  the  directions  given.  Of  the  100 
c.c.  of  the  inverted  solution  thus  obtained,  place  50  c.c. 
in  a  liter  flask  and  make  up  to  1000  c.c.  with  distilled 
water. 

As  100  c.c.  of  the  original  inverted  solution  contain  13.0 
grams  of  the  sugar  solution  to  be  analyzed,  50  c.c.  will 
contain  6.5  gram  of  the  sugar  solution  and  as  these  have 
been  made  up  to  1000  c.c.  each  c.c.  of  this  last  named  solu- 
tion will  contain  0.0065  gram  of  the  sugar  solution  to  be 
analyzed. 

Suppose  now  that  67  c.c.  of  this  solution  have  been 
required  to  decolorize  completely  the  50  c.c.  of  Fehling 


DETERMINATION  BY  CHEMICAL  ANALYSIS       87 

solution  used  in  the  test,  then  those  67  c.c.  of  the  inverted 
sugar  solution  must  also  contain  0.245  gram  of  invert 
sugar.  But  these  67  c.c.  correspond  to  67X0.0065  =  0.4355 
gram  of  the  sugar  solution  used  for  analysis. 

Hence,  0.4355  :  0.245::  100  :  x 

#  =  56.25%  invert  sugar  in  the  sugar  solu- 
tion after  its  inversion. 

As  1.0  part  of  invert  sugar  corresponds  to  0.95  part  of 
sucrose,  56.25X0.95  =  53.44%  sucrose  in  the  solution 
analyzed. 

Gravimetric  Analysis.  Inversion  of  the  sucrose  to  be 
determined  is  conducted  precisely  as  previously  directed 
and  the  Fehling  solution  is  to  be  prepared  as  there  described. 
The  procedure  is  as  follows: 

Weigh  out  13.024  grams  of  the  sample.  Dissolve  with 
about  75  c.c.  of  water  in  a  100  Mohr  c.c.  flask.  Add  5  c.c. 
hydrochloric  acid  (sp.gr.  1.188).  Heat  quickly,  in  two  or 
three  minutes,  on  a  wrater-bath  up  to  69°  C.  Then  keep 
at  this  temperature,  as  close  to  69°  C.  as  possible,  for  five 
minutes,  with  constant  agitation.  Cool  quickly;  make 
up  to  100  c.c.  Remove  50  c.c.  by  a  pipette,  place  in  a  liter 
flask,  and  fill  up  to  1000  c.c.  Of  this  solution  take  25  c.c., 
corresponding  to  0.1628  gram  of  sample,  neutralize  all 
free  acid  present  by  about  25  c.c.  of  a  solution  of  sodium 
carbonate  prepared  by  dissolving  1.7  grams  crystallized 
sodium  carbonate  in  1000  c.c.  of  water.  Then  add  50  c.c. 
of  Fehling's  solution  and  heat  to  boiling  in  the  following 
manner.  Over  the  wire-gauze  above  the  flame  lay  a  sheet 
of  asbestos  provided  with  a  circular  opening  of  about  6.5 
cm.  diameter;  on  this  place  the  flask,  and  arrange  the 
burner  in  such  a  manner,  that  about  four  minutes  are  con- 
sumed in  heating  the  solution  to  the  boiling-point.  From 
the  time  that  the  solution  starts  to  boil — the  moment  when 
bubbles  arise  not  only  from  the  center,  but  also  from  the 
sides  of  the  vessel — continue  to  boil  for  exactly  three  minutes 


88  SUGAR  ANALYSIS 

with  a  small  flame.  Then  remove  the  flask  from  the 
flame  immediately,  and  add  100  c.c.  of  cold  distilled 
water,  from  which  the  air  has  previously  been  removed 
by  boiling.* 

Then  filter  through  an  asbestos  filter,  wash,  and  reduce 
to  metallic  copper  f 

This  operation  is  carried  out  in  the  following  manner: 
Clean  a  small  straight  calcium-chloride  tube,  or  other  tube 
of  similar  pattern  thoroughly.  Introduce  asbestos  fibers  { 
so  as  to  fill  about  half  of  the  bulb.  Draw  air  through 
while  drying,  cool,  and  weigh.  Connect  with  an  aspira- 
tor, filter  the  precipitated  Cu2O,  wash  with  hot  water,  and 
then,  having  changed  the  receiving  flask,  wash  twice  with 
absolute  alcohol  and  twice  with  ether.  Having  removed 
the  greater  part  of  the  ether  by  an  air-current,  connect 
the  upper  part  of  the  filter  tube  by  means  of  a  cork  and 
glass  tubing  with  a  hydrogen  apparatus,  and,  while  the 
hydrogen  gas  is  flowing  through,  cautiously  heat  the  pre- 
cipitate with  a  small  flame  whose  tip  is  about  5  cm.  below 
the  bulb  containing  the  Cu2O.  The  reduction  should 
be  completed  in  from  two  to  three  minutes. 

After  the  tube  has  been  cooled  in  the  current  of  hydro- 
gen, air  is  once  more  drawn  through  and  the  tube  is  then 
weighed. 

After  an  analysis  is  completed,  the  asbestos  is  readily 
freed  from  the  adhering  copper  by  washing  with  dilute 
nitric  acid. 

*  The  water  is  added  to  prevent  subsequent  precipitation  of  cuprous 
oxide. 

t  This  last  step  is  sometimes  omitted,  the  curpous  oxide  being 
weighed  after  washing  and  drying,  and  the  corresponding  amount  of 
copper  calculated  by  multiplying  by  0.8.  This  should  be  done  how- 
ever only  when  the  amount  of  cuprous  oxide  formed  is  not  large. 

t  The  asbestos  must  first  be  prepared  by  washing  successively  with 
a  solution  of  caustic  soda  (not  too  concentrated),  boiling  water,  nitric 
acid,  and  again  with  boiling  water.  When  filled  into  the  glass  tube 
the  asbestos  is  made  to  rest  on  a  perforated  platinum  cone. 


DETERMINATION  BY  CHEMICAL  ANALYSIS       89 

The  use  of  the  electric  current  has  also  been  advocated 
for  reducing  the  precipitate  to  metallic  copper. 

The  cuprous  oxide  is  dissolved  with  20  c.c.  nitric  acid 
(sp.gr.  1.2),  the  solution  is  placed  into  a  weighed  platinum 
dish,  made  up  to  between  150  and  180  c.c.  with  distilled 
water,  and  the  copper  precipitated  by  the  electric 
current. 

Calculation.  In  Table  XI  seek  the  number  of  milli- 
grams of  copper  which  agree  most  closely  with  the  amount 
of  copper  found.  The  corresponding  number  in  the  column 
to  the  left,  shows  at  once  the  number  of  milligrams  of 
sucrose. 

Example.  25  c.c.  of  the  inverted  solution  =  0.1628 
gram  of  sample,  yielded  0.1628  gram  copper.  This  corre- 
sponds to  0.082  gram  sucrose;  hence  there  are  present  in 
the  sample  50.4  per  cent  sucrose. 

If  a  number  of  such  determinations  are  to  be  carried 
out  it  will  prove  convenient  to  construct  a  table  which 
will  indicate  directly  the  percentage  of  sucrose  correspond- 
ing to  the  milligrams  of  copper  found.  Thus  79  mgr. 
copper  correspond  to  40  mgr.  of  sucrose.  As  0.1628  gram 
of  the  sample  has  been  taken  for  analysis, 

0.1628  :  0.0400::  100  :  x 
#  =  24.6%  sucrose. 

Sucrose  in  Condensation,  Boiler-Feed  and  Waste 
Waters.  If  preferred  to  an  optical  determination  the 
sucrose  in  condensation,  waste  waters,  etc.,  may  be  trans- 
formed into  invert  sugar  and  determined  as  such.  To  do 
this  concentrate  the  condensation  water  to  5%  of  its 
original  volume  and  invert  by  means  of  hydrochloric  acid, 
using  1  part  of  cone.  HC1  acid  for  10  parts  of  the  concen- 
trated water.  After  inversion  neutralize  by  sodium  hydrate 
and  determine  the  invert  sugar  formed,  volumetrically  or 
gravimetrically  as  'preferred.  Multiply  the  amount  of 


90  SUGAR  ANALYSIS 

invert  sugar  thus  found  by  0.95  as  95  parts  of  sucrose  on 
inversion  yield  100  parts  of  invert  sugar.  The  result  is 
the  amount  of  sucrose  in  the  sample  of  water  examined. 

Sucrose  and  Invert  Sugar.  If  the  sample  analyzed 
contains  invert  sugar  as  well  as  sucrose,  two  determinations 
with  Fehling's  solution  must  be  made — one  without  inver- 
sion, '  the  other  after  inversion.  The  difference  between 
these  invert  sugar  values  multiplied  by  0.95  represents 
the  sucrose  in  the  sample. 

Sucrose,  Invert  Sugar  and  Levulose  or  Dextrose. 
Fehling's  solution  can  also  be  used — employing  the 
gravimetric  method — to  determine  sucrose,  invert  sugar 
and  levulose  or  dextrose. 

The  necessary  determinations  to  be  made  are  those  of 
the  sucrose,  the  total  reducing  sugars  and  of  the  dextrose 
after  destruction  of  the  levulose  by  Sieben's  process. 

Take  100  c.c.  of  a  solution  made  to  contain  2.5  grams 
on  the  dry  substance  of  invert  sugar,  or  of  invert  sugar 
and  levulose,  place  in  a  flask,  add  60  c.c.  of  a  hydrochloric- 
acid  solution  which  is  six  times  the  strength  of  a  normal 
solution,  and  heat  the  flask  for  three  hours  while  it  is  sus- 
pended in  boiling  water.  After  this  has  been  done,  cool 
immediately,  neutralize  with  a  sodium-hydrate  solution 
which  is  six  times  the  strength  of  a  normal  solution,  make 
up  to  a  volume  of  250  c.c.,  and  filter.  Of  the  filtrate  use 
25  c.c.  for  the  determination  of  the  dextrose;  this  is  obtained 
as  follows: 

Take  30  c.c.  copper-sulphate  solution;  * 
|  30  c.c.  Rochelle-salt  solution;  f 
60  c.c.  water. 

*  Prepared  by  dissolving  69.278  grams  C.P.  sulphate  of  copper 
in  distilled  water,  and  making  the  solution  up  to  1  liter. 

t  Prepared  by  dissolving  173  grams  Rochelle  salt,  cryst.  and  125 
grams  potassium  hydrate  in  distilled  water,  and  making  the  volume 
up  to  500  c.c. 


DETERMINATION  BY  CHEMICAL  ANALYSIS       91 

Heat  to  boiling.  Add  25  c.c.  of  the  solution,  prepared 
as  above,  and  keep  boiling  for  two  minutes.  Then  pro- 
ceed as  with  a  gravimetric  determination  of  invert  sugar. 
Table  XV  shows  the  amount  of  dextrose  corresponding 
to  the  weight  of  copper  found. 

Unfortunately,  however,  the  destruction  of  the  levu- 
lose  by  hydrochloric  acid  (Sieben's  process),  on  which  this 
whole  scheme  of  analysis  is  based,  is  not  always  accom- 
plished with  certainty,  and  the  results  obtained  by  this 
method  must  therefore  be  received  with  some  caution  and 
reserve. 

The  method  of  calculating  the  results  consists  of  two 
steps : 

Step  I.  is  always  the  same,  and  merely  establishes 
whether  the  dextrose  and  the  levulose  are  present  in  the 
proportion  of  1  to  1,  or  whether  either  is  in  excess. 

Step  II.  determines  the  amount  of  this  excess,  be  it  of 
dextrose  or  of  levulose. 

Values  determined: 

No.  1.  Copper  reduced  by  total  sucrose + total  reducing 

sugars. 

No.  2.  "  total  reducing  sugars. 

No.  3.  dextrose  (after  Sieben's  treat- 

ment) . 

CALCULATION. 
Step  I. 

No.  l=Cu   reduced   by   inverted   sucrose    and   total 

reducing  sugars. 
Less  No.  2  =  Cu  reduced  by  total  reducing  sugars. 


Difference  =  Cu  reduced  by  inverted  sucrose.     Report  the 
corresponding  value  as  sucrose. 


92  SUGAR  ANALYSIS 

This  difference  -s-  2  =  Cu  reduced  by  the  dex- 
trose of  the  inverted  sucrose.  Call  this 
value  x. 

No.  3  =  Cu  reduced  by  the  total  dextrose  (after  Sie- 
ben's  treatment). 

Less  x  =  Cu  reduced  by  the  dextrose  of  the  inverted 
sucrose. 


Difference  =  Cu  reduced  by  the  dextrose  of  the  total  re- 
ducing sugars.     Call  this  value  y.     Then, 
t/X2  =  2t/    Cu    reduced    by  invert  sugar + free    dex- 
trose, if  any  is  present. 

Compare  this  value,  2y,  with  No.  2 : 

If  2y  =  No.  2,  invert  sugar  only  is  present.     If  so,  report 

as  invert  sugar. 

If  2?/>No.  2,  free  dextrose  is  present. 
If  2z/<No.  2,  free  levulose  is  present. 


Step  II. 

When  2y>No.  2,  free  dextrose  is  present. 
No.  2  =  Cu  reduced  by  the  total  reducing  sugars. 
Less  y  =  Cu   reduced   by   the    dextrose    from    the   total 
reducing  sugars 


Difference  =  Cu  reduced  by  the  levulose  of  the  total  reduc- 
ing sugars.     Call  this  value  p. 
pX2  =  2p   Cu  reduced  by  invert  sugar.      Report  as 

invert  sugar. 

No.  2  =  Cu  reduced  by  the  total  reducing  sugars. 
Less  2p  =  Cu  reduced  by  invert  sugar. 


Difference  =  Cu  reduced  by  the  free  dextrose. 


DETERMINATION  BY  CHEMICAL  ANALYSIS       93 

Step  II. 

When  2y<No.  2,  free  levulose  is  present. 
No.  2  =  Cu  reduced  by  the  total  reducing  sugars. 
Less  2i/  =  Cu  reduced   by  the  invert  sugar.     Report   as 
invert  sugar. 


Difference  =  Cu  reduced  by  the  free  levulose. 

In  these  calculations  no  attention  has  been  paid  to  the 
fact  that  the  reducing  power  of  invert  sugar,  dextrose, 
and  levulose  for  copper  solutions  is  not  identical,  but  allow- 
ance for  this  can  readily  be  made. 


CHAPTER   VI 

SUCROSE  DETERMINATION  BY  OPTICAL  AND  CHEMICAL 

ANALYSIS 

Sucrose  in  Presence  of  Invert  Sugar.  Method  L 
Determine  the  direct  polarization  as  usual  and  the  amount 
of  invert  sugar  by  means  of  Fehling's  solution.  Express 
the  latter  value  in  terms  of  percentage,  multiply  this  value 
by  0.34  and  add  the  product  to  the  direct  polarization. 

Example. 

Direct  polarization 84 . 00 

Invert  sugar 6 . 00 

6.0X0.34=   2.04 
Direct  Pol.  =84. 00 


Sucrose    =86.04 

Results  so  obtained  are  however  only  approximately  accurate. 

Method  II.  MEISSL-HERZFELD.  Weigh  out  26.048  grams 
of  the  sample.  Place  into  a  100  c.c.  flask,  clarify  with 
basic  acetate  of  lead,  make  up  to  100  c.c.,  filter,  and  polarize. 
Take  an  aliquot  part  of  the  filtrate,  add  sodium  sulphate 
to  remove  any  lead  present,  make  up  to  a  definite  volume, 
and  filter.  It  is  best  to  arrange  the  dilution  so,  that  the 
50  c.c.  of  this  filtrate,  which  are  to  be  used  for  the  determina- 
tion of  the  invert  sugar,  will  precipitate  between  200  and  300 
milligrams  of  copper. 

To  50  c.c.  of  the  sugar  solution  prepared  as  above,  add 
50  c.c.  Fehling's  solution  (25  c.c.  copper  sulphate  and  25 

94 


OPTICAL  AND  CHEMICAL  ANALYSIS  95 

c.c.    of   Rochelle-salt-soda  solution),    and   proceed    as   pre- 
viously directed. 

After  having  determined  the  amount  of  copper  reduced, 
the  method  of  calculating  the  amount  of  invert  sugar, 
corresponding  to  the  weight  cf  copper  found,  can  best  be 
illustrated  by  an  example.  Suppose  that  25  c.c.  of  the 
26.048  grams  of  sugar  dissolved  in  100  c.c.,  had  been  re- 
moved, clarified  with  sodium  sulphate,  made  up  to  100  c.c., 
and  filtered:  50  c.c.  of  this  filtrate  would  correspond  to 
3.256  grams  of  substance. 

Let  this  weight  be  designated  by  the  letter  p. 

The  approximate  amount  of  invert  sugar  may  be  assumed 
to  be 

=  Cu 
2  ' 

The  approximate  percentage  of  invert  sugar  will  be 
=  Cu     100 

Representing  the  former  value  by  Z,  the  latter  by  y, 
we  have 

~~2~' 
and 

Cu     100 


The  ratio  between  the  invert  sugar  and  the  sucrose  is 
determined  by  the  following  formulae,  designating  sucrose 
by  the  letter  S,  and  invert  sugar  by  /. 

s_  100  X  Polarization 
Polarization +y 

7=100-5. 


96  SUGAR  ANALYSIS 

Example.  Polarization  of  26.048  grams  =  86.4.  p  =  3.256 
grams. 

Suppose  these  3.256  grams  have  precipitated,  on  boil- 
ing with  Fehling's  solution,  0.290  gram  of  copper.  Then, 

Cu    0.290 
1.  T.  —  = 

Cu     100  100 


100  X  Pol.  _       8640       _ 
PoL+y    "86.4+4.45" 

100-  S      =/, 
100-95.1=4.9, 
4.9  =  7, 

and  therefore  the  ratio  of  S  :  I  is  expressed  by  95.1  :  4.9. 
In  order  to  find  the  factor  F  we  must  hunt  up  the  cor- 
rect vertical  and  horizontal  columns  in  Table  XIII.  The 
value  Z  =  145  is  most  closely  approximated  by  the  column 
headed  150;  the  ratio  S  :  7  =  95.1  :  4.9  is  most  closely 
approximated  by  the  horizontal  column  95  :  5.  At  the 
line  of  intersection  of  these  two  columns  there  will  be  found 
the  factor  51.2,  by  aid  of  which  the  final  calculation  is 
effected. 

4.  —  XF  =  ^|5x51.2=4.56%  invert  sugar. 


The  analysis  would  hence  show: 

Polarization,         .      .      /  ..  .      .      .86.40 
Invert  sugar,        ......     4.56 

If  duplicate  or  comparative  determinations  of  invert 
sugar  are  to  be  made  by  this  method,  the  same  weight  of 
substance  should  always  be  taken,  Otherwise,  the  value 


OPTICAL  AND  CHEMICAL  ANALYSIS  97 

of  Z  varying,  will  necessitate  the  employing  of  different 
factors,  and  in  consequence  discrepancies  will  ensue. 

Example. 

Weight  used, .     2. 500  grams. 

Polarization,  .      .      .      .      .      .95.00 

Cu  reduced, 0.140 

Invert  sugar  =  2.587  per  cent. 

Weight  used, 5. 000 grams. 

Polarization, 95.00 

Cu  reduced, 0.278 

Invert  sugar  =  2.768  per  cent. 

These  methods  of  determining  invert  sugar  are  based 
on  the  assumption  that  there  are  no  other  substances 
present  besides  invert  sugar  which  will  precipitate  the 
copper  from  its  solution. 

Sucrose  in  Presence  of  Dextrose  and  Levulose.*  This 
method  involves  but  three  simple  analytical  operations: 
two  gravimetric  determinations,  and  one  optical  examina- 
tion with  the  polariscope,  is  therefore  easy  and  rapid  of 
execution,  and,  with  careful  manipulation,  yields  accurate 
results 

THE  METHOD. 

Preparation  of  Solution.  If  not  already  in  solution, 
make  of  the  sample  to  be  examined  a  solution  of  arbitrary 
density.  Of  course,  it  goes  without  saying,  that  this 
method  is  to  be  applied  only  in  cases  where  no  other  optically 
active  substances  are  present  besides  sucrose,  dextrose 
and  levulose,  and  that  care  must  be  exercised  that  no  pre- 
liminary treatment  of  the  solution  shall  influence  its  original 
power  of  rotation. 

*Wiechmann,  School  of  Mines  Quarterly,  Vol.  XIII,  No.  3. 
International  Sugar  Journal,  1907,  Vol.  IX,  p.  68. 


98  SUGAR  ANALYSIS 

The  specific  gravity  of  the  solution  above  referred  to 
is  accurately  determined  by  balance,  and  from  this  value 
there  are  calculated,  in  the  following  manner,  the  number 
of  grams  of  solution  which  contain  10.000  grams  of  dry 
substance:* 

Ascertain  the  degree  Brix  corresponding  to  the  specific 
gravity  found.  Divide  100  by  the  degree  Brix;  the  quotient 
represents  the  number  of  grams  of  solution  which  contain 
1.00  gram  of  dry  substance.  This  value  is  multiplied  by 
10,  and  the  product  represents  the  number  of  grams  of 
solution,  equivalent  to  10.000  grams  of  dry  substance. 

This  amount  is  weighed  out,  placed  in  an  accurately 
graduated  100  c.c.  flask,  and  the  solution  in  the  flask  is 
made  up  to  100  c.c.  with  distilled  water. 

The  determinations  to  be  made,  are  as  follows: 

Optical  Examination.  Some  of  the  solution  is  placed  in  a 
water-jacketed  polarization  tube,  a  thermometer  is  inserted 
in  the  solution,  and  a  reading  on  this  solution  is  taken  in 
the  polariscope,  at  the  temperature  of  20°  C. 

The  reading  thus  obtained  must  be  reduced  to  the  basis 
of  a  reading  made  in  a  100  m.m.  tube. 

Furthermore,  if  a  sugar  polariscope  has  been  used  for  the 
observation,  the  reading  obtained  must  be  transformed 
into  circular  degrees.  With  a  polariscope  using  26.048 
grams  as  the  normal  weight,  the  factor  0.346  is  used,  for 
the  sodium  ray. 

Gravimetric  Determination  before  Inversion.  Of  the  10 
per  cent  solution,  weigh  out  an  amount  equivalent  to  1.0 
gram  of  dry  substance.  Make  this  up  to  150  c.c.,  and  of 
this  solution  take  24.4  c.c.,  equivalent  to  0.1628  gram  dry 
substance.  Take  50  c.c.  of  Fehling's  solution,  heat  to 
boiling;  while  boiling  add  the  24.4  c.c.  of  sugar  solution, 
and  boil  for  three  minutes. 

*  This  concentration  is  chosen  because  the  specific  rotatory  powers 
of  the  sugars,  values  needed  in  the  calculation  of  results,  vary  with 
the  concentration. 


OPTICAL  AND  CHEMICAL  ANALYSIS  99 

Then  remove  from  flame,  add  cold  distilled  water, 
previously  boiled,  in  order  to  cool  the  solution  and  prevent 
a  further  deposition  of  cuprous  oxide. 

Filter  through  a  weighed  asbestos  filter,  wash  first  with 
boiling  water,  then  with  absolute  ethyl  alcohol,  and  finally 
with  ether.  Dry  perfectly,  cool  and  weigh. 

Calculate  the  cuprous  oxide  to  its  equivalent  of  metallic 
copper,  and  from  the  copper  thus  found,  ascertain  the 
corresponding  amount  of  sucrose.*  From  this  figure  the 
total  reducing  sugars  by  adding  ^  to  the  sucrose  value 
indicated. 

Gravimetric  Determination  after  Inversion.  Of  the  original 
10  per  cent  solution,  weigh  off  an  amount  equal  to  5.000 
grams  dry  substance;  invert  with  4  c.c.  of  concentrated 
HC1  (specific  gravity  1.20)  by  heating  on  boiling  water- 
bath  up  to  a  temperature  of  69°  C.  and  maintaining  the 
solution  at  that  temperature  for  five  minutes.  Then  remove 
the  flask,  cool  it  and  its  contents  to  the  temperature  at  which 
the  flask  was  graduated,  and  then  make  the  solution  up 
to  100  c.c. 

Of  the  solution  thus  obtained  take  20  c.c.  and  neutralize 
with  sodium  carbonate;  then  make  up  to  a  volume  of  150 
c.c.  with  distilled  water;  of  this  solution  take  24.4  c.c., 
equivalent  to  0.1628  gram  of  dry  substance,  and  proceed 
precisely  as  previously  directed.  Determine  the  value 
found,  as  before,  from  the  table;  the  result  obtained  repre- 
sents the  total  sugars  present,  expressed  as  sucrose.  From 
this  amount  subtract  the  sucrose  value  found  by  prior 
determination,  f  and  the  difference  represents  the  amount 
of  sucrose  actually  present. 

The  results  thus  obtained  represent:  the  polarization, 
in  a  10  per  cent  solution,  of  the  three  sugars  combined; 

*  Table  published  by  the  German  Government,  Table  XI. 
f  That  is,  the  amount  as  actually  found  by  table,  prior  to  the 
addition  of  -2V 


100  SUGAR  ANALYSIS 

the  total  reducing  sugars  present;    the  amount  of  sucrose 
present. 

In  cases  where  the  reducing  sugars,  i.e.,  the  dextrose 
and  the  levulose  together,  exceed  in  amount  the  sucrose 
present,  the  gravimetric  determinations  before  and  after 
inversion  should  preferably  be  made  according  to  E.  MeissPs 
method  for  the  determination  of  invert  sugar.  * 

CALCULATION  OF  THE  RESULTS  OF  ANALYSIS. 

This  can  be  accomplished  by  algebra,  or  by  allegation. 

BY  ALGEBRA. 

Let: 

a  =  amount  of  sucrose  present. 
6  =  amount  of  total  reducing  sugars  present. 
x  =  amount  of  dextrose  present. 
y  =  amount  of  levulose  present. 

s  =  the  specific  rotatory  power  of  sucrose,  divided  by  100. 

d  =  the  specific  rotatory  power  of  dextrose,  divided  by  100. 

Z  =  the  specific  rotatory  power  of  levulose,  divided  by  100. 

p  =  polarization  observed,  expressed  in  circular  degrees. 

Then 

(as+xd)-yl  =  p. 
(as+xd)=p+yl. 


_p+yl  — 


d 
Substituting  this  value  of  x  in  the  equation 

x+y  =  b 

*  Zeitschrift  des  Vereines  fur  Rubenzucker-industrie,  Vol.  XXIX, 
p.  1034,  and  E.  Wein:  Tabellen  zur  Quantitatuen  Bestimmung  der 
Zuckerarten. 


OPTICAL  AND  CHEMICAL  ANALYSIS  101 

there  results: 


p+yl—  as+yd  =  bd. 

yl-\-yd  =  bd  —  p-\-as. 

y(l-\-d)  =  bd  — 

bd—p+as 


As  y  represents  the  amount  of  levulose,  y  deducted  from 
b  will  give  at  once  the  amount  of  dextrose.  Or,  if  preferred, 
the  value  of  x  can  also  easily  be  calculated  independently. 

Example. 

Sucrose  —  a  =  8.  50. 

Total  reducing  sugars  =  b  =  1.50. 

Polarization,  expressed  in  circular  degrees  =  p  =  5.  6426. 

Specific  rotatory  power  of  sucrose  -5-  100  =  s=  +0.665. 

Specific  rotatory  power  of  dextrose  -s-1  00  =  d=  +0.535. 

Specific  rotatory  power  of  levulose  +100  =  1=  —0.819. 

Dextrose  present  =  x. 

Levulose  present  =  y. 

(8.50  X.  665+zX.  535)  -(yX.  819)  =5.6426. 

(8.50X.665+xX.535)=5.6426+(7/X.819). 
.535z  =  5.6426+  .819y  -  5.6525. 

m       _-O.Q099+.819y 

(2). 


Substituting  the  value  of  x  found  in  equation  (1),  in 
equation  (2),  there  results: 


-0.0099+.819?/  =  0.8025. 
1.354y  =  0.8124. 
y  =0.600. 


102  SUGAR  ANALYSIS 

Total  Reducing  sugars  present,       .      .  =  1 . 50 

Levulose  present,       .      .      .    •  .  „    .      .  =  0 . 60 

Dextrose  present, =  0 . 90 


BY  ALLEGATION. 

Example. 

Determinations  made  on  a  10  per  cent  solution. 

Per  cent. 

Sucrose  present,         =   66 . 0 

Total  Reducing  sugars  present,        .      .  =   34 . 0 
Polarization  observed,  .=   2.8199 

Polarization    due    to    the    sucrose  =  6. 6  X 
0.665, •     .=  4.3890 

Difference  due  to  the  3.40  per  cent 

Reducing  sugars, =   1.5691 

34  :  100::  1.5691  :  x 
156.91-^34  =  -4.615. 

+53.5  35.75 

V-46.15 
-81.9  99.65 

135.40 

135.4  :  35.75::  34  :  a:  =  8.98  per  cent  of  dextrose. 
135.4  :  99.65::  34  :  #  =  25.02  per  cent  of  levulose. 

Or  else,  having  found  the  percentage  of  dextrose  as  above, 

Per  eent. 

Total  Reducing  sugars,       .      .      .      .  =  34 . 00 
Dextrose  present, =     8 . 98 

Levulose  present, =  25 . 02 


OPTICAL  AND  CHEMICAL  ANALYSIS  103 

As  to  reporting  the  nature  of  the  reducing  sugars,  the 
analysis  of  course  only  warrants  the  stating  of  the  actual 
amounts  of  sucrose,  of  dextrose,  and  of  levulose  as  found. 

Should  it,  however  be  so  desired,  equal  quantities  of 
dextrose  and  levulose  might  be  considered  as  present  in 
the  form  of  invert  sugar. 

The  dextrose  or  the  levulose,  of  whichever  one  least  is 
found,  might  be  regarded  as  combined  with  an  equal  amount 
of  the  other,  forming  invert  sugar,  and  any  excess  over 
the  amount  so  disposed  of,  could  be  reported  as  free,  or 
uncombined  dextrose,  or  levulose,  as  the  case  might  be. 

Sucrose  in  Presence  of  Invert  Sugar  and  Raffinose. 
The  following  method  is  due  to  J .  Baumann  and  is 
based  on  the  following  considerations. 

The  reading  of  the  normal  weight  of  pure  sucrose  after 
inversion  is  =-32.66°  V.  at  20°  C.  If  x%  of  sucrose  are 
present  a  reading  of  —  .3266a;0  V.  will  be  obtained;  y% 
of  anhydrous  raffinose  will  after  inversion  produce  a 
rotation  of  0.9491°  V. 

Let  a  mixture  of  sucrose,  invert  sugar  and  raffinose, 
contain,  for  instance,  x%  sucrose + invert  sugar  (figured 
as  sucrose)  and  y%  raffinose  then,  if  P'  denotes  the 
polarization  after  inversion, 

1.  P1  =  -0.3266z+0.9491y. 

Assuming  that  0.1628  gram  of  the  mixture  be  inverted 
and  tested  with  Fehling's  solution  the  x%  of  sucrose  will 
reduce 

0.1628XFi  , 

— x  grams  of  copper 

1UU 

FI   being  the  reducing  factor  of  inverted  sucrose.     In  a 
similar  manner  y%  of  raffinose  will  yield 

0.1628XF2 

-jjjg y  grams  of  copper, 

F2  being  the  reducing  factor  of  the  inverted  raffinose. 


104  SUGAR  ANALYSIS 

Having  present  x%  of  sucrose  +  invert  sugar  (figured 
as  sucrose)  and  y%  of  raffmose,  then,  representing  the 
total  amount  of  copper  precipitated  by  Cu, 

r       0.1628X^1     ,  0.1628/^2 

—  x—~ 


From  these  two  equations  there  is  deduced: 
94.91 


0.1628 
x 


Cu-P'F2 


y= 


0.9491/^1 +0.3266/<2 

P'+0.3266a 
0.9491 


From  these  expressions  the  following  formulae  are 
derived. 

Let,  S  =  Total  sucrose,  i.e.,  sucrose + invert  sugar  figured 

as  sucrose, 
/2  =  Raffinose  (anhydrous), 

then, 

„       582.98  Cu-P'F2 
0.9491Fi +0.3266F2 

ff  =  1.054P'+0.344S. 

The  factors  for  F\  are  obtained  from  Table  XI  by  finding 
therein  the  amount  of  copper  obtained  and  dividing  this 
value  by  the  corresponding  amount  of  sucrose. 

The  factors  for  F%  are  given  in  a  table  published  in  the 
Zeitschrift  des  Vereins  fur  Riibenzucker-Industrie,  1888, 
Vol.  XXXVIII,  p.  741. 

It  is  not  necessary  however  to  have  these  constants  for 
every  instance;  it  will  answer  to  calculate  these  for  every 
10  milligrams  of  copper.  The  following  table  gives 


OPTICAL  AND  CHEMICAL  ANALYSIS  105 

values  calculated  for  copper  ranging  from  150  to  200  milli- 
grams. 

Cu=  S= 


0.150  248.  iXCu-  0.605  XP' 

0.160  248.4  XCu- 0.604  XP' 

0.170  248.7  XCu- 0.604  XP' 

0.180  249.2XCu-0.604XP' 

0.190  249.7XCu-0.604XP' 

0.200  250.0  X  Cu  -  0.604  XP' 

#  =  1.054P'+0.344S 

If  the  customary  amount  of  substance,  0.1628  gram 
has  not  been  used  for  the  determination  of  the  inverted 
sugars,  but,  say  w  gram,  the  copper  value  found  must  be 

multiplied  by  -     —  and  the    resultant  value  used  in  the 

above  given  formula?  in  place  of  the  other  Cu  value.  For 
the  calculation  of  the  reduction  factors  however  the  actual 
weight  of  the  precipitated  copper  must  be  employed. 

In  order  to  determine  the  sucrose  and  the  invert  sugar 
separately,  in  addition  to  the  raffinose,  an  invert  sugar 
determination  must  be  made  as  usual,  however  instead 
of  using  the  direct  polarization  for  calculating  the  factor 
F  the  total  sucrose  value  obtained  by  the  formulae  previously 
given  must  be  used. 

One-twentieth  must  be  deducted  from  the  invert  sugar 
formed,  to  express  it  in  terms  of  sucrose,  and  this  remain- 
der, subtracted  from  the  total  sucrose  will  represent  the 
sucrose  present  as  such. 

Example.  Analysis  of  a  syrup  yielded  the  following 
data: 

Polarization  after  inversion,  P' '=  —8.5° 

0.1628  gram  of  sample  gave  after  inversion  Cu  =  0.184  gram 
2.000  grams  of  sample  gave  before  inversion  Cu  =  0.250  gram 


106  SUGAR  ANALYSIS 

The  figure  Cu  =  0.184  is,  in  the  table  previously  given, 
approximated  most  closely  by  the  figure  Cu  =  0.180  and 
for  this  value 

S  =  249.2Cu-0.604P' 

Hence,          S  =  249.2  X  0.184  -0.604(-  8.5)  =50.98 
#  =  1.054(-8.5)+0.344(50.98)=8.58 

To  determine  the  ratio  of  the  sucrose,  S,  to  the  invert 
sugar,  /, 


hence,  S+I  :  7::50.98  :  6.25::  100  :  12 

S:I::  88  :  12 


6.58 

_    1     _  Q  gg 

*T    —•  —   and  this  value  must  be  subtracted  from  the 
6.25 

total  sucrose,  i.e.,  50.98-6.25  =  44.73. 
The  syrup  therefore  contains: 

Sucrose  =44.73% 
Invert  sugar  =  6.58% 
Raffinose  =  8.58% 


CHAPTER  VII 
CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE 

Reducing  Sugars  in  General.  A  valuable  reagent  for 
the  detection  of  reducing  sugars,  for  instance,  of  dextrose 
and  levulose,  is  phenyl  hydrazine  H^N  —  NHCeHs.  Emil 
Fischer,  in  1884,  first  directed  attention  to  this  reagent  for 
the  purpose. 

All  sugars  which  contain  a  free  carbonyl  group  respond 
to  this  test,  giving  compounds  which  are  termed  hydra- 
zones. 

Hydrazones  are  prepared  by  adding  to  the  sugar  solu- 
tion, while  cold,  a  solution  consisting  of  equal  volumes  of 
phenyl  hydrazine  and  a  50%  acetic  acid  solution  and  three 
volumes  of  water.  The  hydrazones  separate  as  crystalline 
compounds,  some  of  them  almost  at  once,  others  after  a 
longer  time,  that  of  glucose  possibly  only  after  a  day  or 
two.  Purification  is  effected  by  recrystallization  from 
water  or  from  alcohol,  the  purity  of  the  product  being 
proven  by  its  exhibiting  a  constant  melting-point.  The 
sugars  are  separated  from  their  hydrazones  either  by  the 
use  of  concentrated  hydrochloric  acid  or  by  means  of 
formaldehyde;  in  the  former  case  phenyl  hydrazine  chloride 
and  free  sugar  are  formed.  The  former  substance  is 
removed  by  filtration,  and  the  filtrate  after  neutralization 
with  carbonate  of  lead  and  filtration  is  evaporated  to  a 
syrup.  This  is  then  shaken  up  with  alcohol,  95%  strength, 
refiltered  and  the  filtrate  allowed  to  crystallize  by  evapo- 
ration. 

107 


108 


SUGAR  ANALYSIS 


If  a  reducing  sugar  be  heated  with  an  excess  of  phenyl- 
hydrazine  a  dihydrazone,  usually  termed  an  osazone,  is 
formed.  Osazones  are  but  slightly  soluble  in  water  they 
crystallize  well  and  have  definite  melting-points. 

Dissolve  in  20  parts  of  water,  one  part  of  the  sugar  to  be 
tested,  two  parts  of  pure  phenyl  hydrazirie  hydrochloride 
and  three  parts  of  cryst:  sodium  acetate.*  Place  test-tube 
and  contents,  loosely  corked,  into  boiling  water  the  solu- 
tion being  occasionally  stirred  to  facilitate  crystallization. 

All  of  the  monosaccharides  form  precipitates  within 
20  minutes.  Maltose  and  lactose  yield  precipitates  only 
on  cooling  the  solution.  Sucrose  will  yield  a  precipitate 
only  after  it  has  been  changed  to  dextrose  and  levulose — 
this  is  effected  only  after  heating  for  about  30  minutes  in 
the  water-bath. 

One  to  two  hours'  heating  in  the  bath  and  then  cooling 
the  solution  produces  the  largest  yield  of  osazones.  The 
osazones  usually  have  a  yellow  color,  and  can  be  purified 
by  recrystallization  from  50%  boiling  alcoholic  solution. 
The  osazones  of  the  monosaccharides  crystallize  from  hot 
solutions,  those  of  the  disaccharides  only  after  cooling. 

The  osazones  yielded  by  some  of  the  more  important 
sugars  are: 


Sugar. 

Osazone. 

Melting-point 
(when  reached  in 
3  or  4  minutes). 

Dextrose 

Glucosazone 

204°-205°  C. 

Levulose 

<  < 

Mannose 

" 

Galactose 

Galactosazone 

193°  C. 

Maltose 

Maltosazone 

206°  C. 

Lactose 

Lactosazone 

200°  C. 

Xylose 
Arabinose 

Xylosazone 
Arabinosazone 

160°  C. 
160°  C. 

*  H.  C.  Sherman,  School  of  Mines  Quarterly,  1905,  p.  148. 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE     109 

Careful  tests  made  by  R.  H.  Williams  showed  that 
solutions  of  pure  dextrose  yielded  the  osazone  in  5  minutes' 
time  when  0.10  gram  was  present,  whereas  17  to  19  minutes 
were  required  when  only  0.01  gram  was  present.  Sucrose 
had  no  appreciable  influence  on  the  result  even  when  present 
up  to  ten  times  the  amount  of  dextrose  present. 

The  reaction  by  which  an  osazone  is  formed  is  probably 
indicated  by  the  empirical  equation: 


Phenyl-Dextrosazone 

The  hydrogen  does  not  escape  but  is  taken  up  by  any 
excess  of  phenyl  hydrazine  which  breaks  up  into  ammonia 
and  aniline. 

All  phenyl  hydrazones  are  changed  to  osazones  on  being 
heated  with  an  excess  of  phenyl  hydrazine. 

Maquenne  pointed  out  that  the  weight  of  osazones 
produced  under  identical  conditions  was  a  characteristic 
of  value.  The  following  weights  of  osazones  were  obtained 
by  heating  for  one  hour  at  100°  C.  1.0  gram  of  sugar  with 
100  grams  of  water  and  5  c.c.  of  a  solution  containing  40 
grams  of  phenyl  hydrazine  and  40  grams  of  acetic  acid  in 
100  c.c. 

After  cooling  the  liquid,  the  osazones  were  placed  upon 
a  weighed  filter,  washed  with  100  c.c.  of  water,  and  dried 
at  110°. 

Sugar.  Weight  of  Osazone. 

Sorbine  crystallized       ......  0.82 

Levulose         "               ......  0.70 

Xylose     ..........  0.40 

Glucose,  anhydrous       ......  0.32 

Arabinose,  crystallized       .....  0.27 

Galactose            "                .....  0.23 

Rhamnose           "                .....  0.15 

Lactose           .    "                .....  0.11 

Maltose  "  .0.11 


110  SUGAR  ANALYSIS 

Invert  Sugar  is  composed  of  equal  parts  of  dextrose  and 
levulose.  Its  formation  from  sucrose  by  inversion  is 
expressed  by  the  reaction: 


Ci2H22Oii  +H20  = 

Sucrose  Water  Dextrose  Levulose 

Invert  sugar 

Qualitative  Test.  A  qualitative  test  for  the  presence  of 
invert  sugar  is  easily  effected  by  the  use  of  methyl  blue. 
To  prepare  this  reagent  dissolve  1.0  gram  of  methyl  blue 
in  1  liter  of  water.  To  test  for  the  presence  of  invert 
sugar,  dissolve  20  grams  of  the  sugar  in  water,  add  basic 
acetate  of  lead  solution,  make  up  to  100  cubic  centimeters, 
and  filter.  Make  the  nitrate  slightly  alkaline  with  a  10 
per  cent  solution  of  sodium  carbonate,  and  filter  again. 
Of  this  filtrate  take  50  cubic  centimeters,  representing 
about  10  grams  of  the  sugar  tested,  place  in  a  porcelain 
casserole,  and  add  2  drops  of  the  methyl-blue  solution. 
Then  place  the  casserole  over  a  naked  flame,  and  note  ac- 
curately when  the  solution  begins  to  boil. 

If  the  solution  is  decolorized  by  boiling  inside  of  one 
half  minute,  there  is  sufficient  invert  sugar  present  to 
permit  of  a  quantitative  determination.  If  it  requires 
from  one  half  to  three  minutes  boiling  to  effect  disap- 
pearance of  the  blue  color,  traces  of  invert  sugar  are  to 
be  reported;  and  if  decolorization  does  not  take  place 
within  three  minutes,  "  no  invert  sugar  "  is  recorded. 

If  the  normal  weight  has  been  dissolved  up  to  100 
c.c.,  20  c.c.  of  the  solution,  clarified  by  basic  acetate  of 
lead,  are  made  up  to  50  c.c.  The  lead  is  removed  by  add- 
ing five  drops  at  a  time  of  the  sodium-carbonate  solution, 
and  the  addition  of  this  reagent,  in  the  same  quantity,  is 
continued,  until  no  more  precipitation  can  be  detected. 

To  25  c.c.  of  the  filtrate  one  drop  of  the  methyl-blue 
solution  is  added;  about  10  c.c.  of  this  solution  are  kept 
actively  boiling  over  a  naked  flame  for  one  minute. 


CONSTITUENTS  OF  SUGAE  OTHER  THAN  SUCROSE     111 


If,  after  thus  boiling  for  one  minute,  the  solution  is 
completely  decolorized,  it  must  have  contained  at  least 
0.01  per  cent  of  invert  sugar.  If  it  is  not  decolorized,  it 
contained  no  invert  sugar,  or  certainly  less  than  0.01 
per  cent. 

Quantitative  Determination.     The  quantitative  determina- 
tion of  invert  sugar  is  effected  by  means  of  alkaline  copper 
solutions    either    volumetric    or    gravimetric 
methods  being  employed. 

Full  details  of  these  methods  have  been 
given  in  Chapters  V  and  VI.  As  there 
directed  keep  the  sulphate  of  copper  solution 
in  one  flask,  and  the  Rochelle-salt-soda 
solution  in  another.  Mix  the  two  immedi- 
ately before  use.  It  will  be  found  very 
convenient  to  have  the  solutions  in  flasks 
or  jars  provided  with  a  siphon-arrangement, 
and  to  have  the  delivery-tube  so  graduated 
that  the  required  amount  may  be  rapidly, 
yet  accurately  measured  out.  The  accom- 
panying figure  shows  an  arrangement  answer- 
ing this  purpose. 

The  standardizing  of  Fehling's  solution 
has  previously  been  fully  discussed  yet  it 
may  be  of  interest  to  add  the  following.* 

"  For  the  standardization  of  a  solution  for 
the  determination  of  invert  sugar  in  sugar- 
house  products,  dissolve  2.5  grams  of  pure 
sucrose  in  100  c.c.  of  water,  add  10  c.c.  of 
hydrochloric  acid  (specific  gravity  1.188), 
and  invert  according  to  the  method  given 
for  double  polarization.  Neutralize  the  acid 
with  sodium  carbonate  and  dilute  to  1  liter.  The  2.5 
grams  of  sucrose  become  2.6316  grams  of  invert  sugar. 


FIG.  7. 


Bulletin  No.  38,  U.  S.  Dept.  of  Agriculture,  Division  of  Chemistry. 


112  SUGAR  ANALYSIS 

The  weight  of    invert  sugar  equivalent  to   10  c.c.  of  the 
copper  reagent  is  calculated  as  follows: 

2.6316  X  by  number  of  c.c.  of  the  standard  sugar  solution  used 

1000 


the  weight  of  invert  sugar  required  to  completely  precipitate 
the  copper  in  10  c.c.  of  the  reagent  under  the  conditions 
used  for  the  test  tit-ration.  For  the  calculation  of  the  result 
of  the  titration  of  an  unknown  solution: 

Let  X  =  the  factor  obtained  as  above; 

F  =  the  number  of  c.c.  of  unknown  sugar  solution 
required  to  precipitate  the  copper  from  10 
c.c.  of  copper  solution; 

W  =  the  weight  of  the  material  under  examination  in 
1  c.c.  of  the  solution. 

100-XT 
Then  ~™  =  per  cent  of  invert  sugar  in  the  sample. 


"  The  calculation  can  be  much  simplified  by  so  standardiz- 
ing the  copper  reagent  that  50  milligrams  of  invert  sugar  will 
be  required  to  reduce  the  copper  from  10  c.c.  of  the  copper 
reagent.  The  various  tables  given  in  works  on  sugar  analysis 
then  become  applicable.  These  tables  are  arranged  for  a 
*  glucose  normal  solution  '  containing  5  grams  of  the 
material  to  be  examined  in  100  c.c.  When  the  weight  per 
100  c.c.  is  more  or  less  than  5  grams  the  number  found  in 
the  table  is  increased  or  diminished  accordingly." 

a.  By  volumetric  analysis.  The  details  of  procedure 
have  been  so  fully  given  in  Chapter  V  in  describing  the 
determination  of  sucrose  (after  inversion)  that  it  will  suf- 
fice to  give  here  in  briefest  outline  the  course  to  be 
followed. 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE     113 

Five,  ten  or  more  grams  of  sugar  are  weighed  out,  dis- 
solved in  a  flask,  and  the  solution  made  up  to  100  c.c. 
The  weight  of  sugar  varies,  of  course,  with  the  nature  of 
the  sample  examined,  that  is  to  say,  with  the  amount  of 
invert  sugar  it  contains.  It  is  advantageous  to  have  the 
solution  of  such  a  strength  that  20  c.c.  to  50  c.c.  will  com- 
pletely precipitate  the  copper  in  10  c.c.  of  the  Fehling 
solution. 

Ten  c.c.  of  the  Fehling  solution  are  measured  out  (using 
5  c.c.  each  of  the  copper  sulphate  and  of  the  Rochelle-salt- 
soda  solution),  placed  in  a  porcelain  dish,  and  quickly 
brought  to  the  boiling  point.  The  sugar  solution  is  then 
run  in  from  a  burette  (graduated  in  tenths  of  a  cubic  centi- 
meter) until  all  of  the  copper  in  the  solution  is  precipitated 
as  cuprous  oxide.  The  operator  is  warned  of  the  approach 
of  the  end  of  the  reaction  by  the  change  in  the  color  of 
his  solution.  The  blue  color  disappears  and  the  solution 
becomes  colorless,  or,  if  the  sugar  solution  is  colored,  assumes 
a  yellow  tinge. 

The  end-point,  however,  is  determined  by  filtering  a 
few  drops  of  the  solution  through  paper  or  linen-cloth 
into  a  very  dilute  solution  of  potassic  ferrocyanide  and 
acetic  acid. 

If  a  brownish-red  color  shows,  owing  to  the  forma- 
tion of  cupric  ferrocyanide,  two  tenths  c.c.  more  of  the 
sugar  solution  are  added  to  the  copper  liquor,  the 
solution  is  again  boiled,  and  the  test  repeated.  This 
is  continued  until  the  addition  of  a  few  drops  of  the 
solution  to  the  ferrocyanide  no  longer  produces  the  red 
color. 

As  10  c.c.  of  the  copper  solution  are  assumed  to  cor- 
respond to  0.05  gram  of  invert  sugar,  the  calculation  is 
an  easy  one.  If  5  grams  of  sugar  have  been  dissolved 
up  to  100  c.c.,  the  reciprocal  of  the  number  of  cubic  cen- 
timeters required  of  this  solution  to  precipitate  all  of  the 
copper  in  10  c.c.  of  the  copper  liquor,  multiplied  by  100, 


114  SUGAR  ANALYSIS 

is  the  direct  percentage  of  invert  sugar  sought.  (See 
Table  XII.) 

Example.  Dissolved  5  grams  of  sugar  in  100  c.c.  Of 
this  solution  used  22  c.c.  to  precipitate  all  of  the  copper 
in  the  Fehling  solution.  Referring  to  Table  XII,  22  c.c. 
will  be  found  to  correspond  to  4.55  per  cent  of  invert  sugar; 
hence  there  is  this  amount  of  invert  sugar  present  in  the 
sample. 

b.  By  gravimetric  analysis.  This  method  also  has  been 
previously  discussed.  Where  very  small  amounts  of  invert 
sugar  are  to  be  determined — in  beet  sugars  for  instance, 
containing  1%  or  less  of  invert  sugar,  the  following  method 
is  applicable.  The  solution  of  the  material  to  be  examined 
is  so  prepared  as  to  contain  20  grams  in  100  c.c.,  and  must 
be  freed  from  suspended  impurities  by  nitration  through 
paper.  In  a  beaker  of  250  c.c.  capacity  place  50  c.c.  of  the 
mixed  copper  reagent  and  50  c.c.  of  the  sugar  solution. 
Heat  this  mixture  at  such  a  rate  that  approximately  three 
minutes  are  required  to  bring  it  to  the  boiling  point  and  then 
continue  to  boil  for  exactly  two  minutes  more.  Add  100  c.c. 
of  cold,  recently  boiled,  distilled  water.  Filter  immediately 
under  pressure  through  a  weighed  filtering  tube  of  hard 
glass.  The  asbestos  film  in  the  filtering  tube  is  supported 
by  a  perforated  disc  or  cone  of  platinum  and  should  be 
moistened  previous  to  the  filtration.  The  precipitate  is 
all  transferred  to  the  filter  and  thoroughly  washed  with 
hot  water,  following  the  water  by  alcohol  and  ether  succes- 
sively. After  being  dried  the  tube  is  connected  with  an 
apparatus  for  supplying  a  continuous  current  of  dry  hydro- 
gen, gently  heated  until  the  cuprous  oxide  is  completely 
reduced  to  the  metallic  state,  cooled  in  the  current  of 
hydrogen,  and  weighed.  The  increase  in  weight  represents 
the  weight  of  copper  reduced  by  10  grams  of  the  sample. 
The  corresponding  percentage  of  invert  sugar  is  found 
by  use  of  the  following  table: 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    115 


HERZFELD'S  TABLE  FOR  THE  DETERMINATION  OF 
INVERT  SUGAR  IN  MATERIALS  CONTAINING  1  PER 
CENT  OR  LESS  OF  INVERT  SUGAR 


Copper 
Reduced  by 
10  grams  of 
Material. 
Milligrams. 

Invert 
Sugar. 

Per  Cent. 

Copper 
Reduced  by 
10  Crams  of 
Material. 
Milligrams. 

Invert 
Sugar. 

Per  Cent. 

Copper 
Reduced  by 
10  Grams  of 
Material. 
Milligrams. 

Invert 
Sugar. 

Per  Cent. 

50 

0.05 

120 

0.40 

190 

0.79 

55 

0.07 

125 

0.43 

195 

0.82 

60 

0.09 

130 

0.45 

200 

0.85 

65 

0.11 

135 

0.48 

205 

0.88 

70 

0.14 

140 

0.51 

210 

0.90 

75 

0.16 

145 

0.53 

215 

0.93 

80 

0.19 

150 

0.56 

220 

0.96 

85 

0.21 

155 

0.59 

225 

0.99 

90 

0.24 

160 

0.62 

230 

1.02 

95 

0.27 

165 

0.65 

235 

1.05 

100 

0.30 

170 

0.68 

240 

1.07 

105 

0.32 

175 

0.71 

245 

1.10 

110 

0.35 

180 

0.74 

115 

0.38 

185 

0.76 

Such  quantitative  determination  should  be  made  on 
all  beet  sugars  which  react  acid  to  the  phenol  phthalei'n  test 
or  which  darken  materially  in  the  vacuum  oven. 

Water.  Weigh  out  2  to  10  grams  of  the  sample.  If 
the  determination  is  to  be  made  on  a  rather  moist  sugar 
or  on  a  syrup,  a  corresponding  amount  of  perfectly  dry 
powdered  glass  or  of  sand  must  be  intimately  mixed  with 
the  sample. 

Place  in  an  air-bath,  the  heating  of  which  should  be 
commenced  only  after  the  introduction  of  the  assay.  The 
heat  should  be  gradually  carried  up  to  100°  C.,*  and  con- 
tinued at  that  temperature  until  the  sample  has  attained 
to  practically  constant  weight,  f 

*  German  and  Belgium  chemists  recommend  a  temperature  of 
not  less  than  105°  C. 

t  Until  the  loss  of  weight  in  one  hour  is  not  greater  than  0.20  per 
cent. 


116  SUGAR  ANALYSIS 

The  loss  in  weight  sustained,  represents  the  water. 

Example.     Weight  of  dish,  sand,  and  sample,       23 . 0000 
"         and  sand,    .      .      .     18.0000 

Sample  taken, 5.0000 

Original  weight  of  dish,  sand,  and  sample,       .      .     23 . 0000 
Final  weight  (after  drying  to  constant  weight),     .     21 . 1546 

Water  =   1.8451 
5.000  :  1.8454::  100  :  x. 
#  =  36.91  per  cent  water. 

Various  drying  ovens  have  been  devised  in  which  water 
determinations  can  be  quickly  made. 

Instead  of  drying  in  an  air-bath,  the  drying  can  be 
done  in  a  current  of  any  inert  gas,  or  it  can  be  still  more 
rapidly  accomplished  by  drjdng  in  a  vacuum.  A  tube 
provided  with  a  number  of  small  branch-tubes,  each  of 
which  can  be  closed  independently  by  means  of  a  stop- 
cock, is  put  into  connection  with  a  vacuum-pump.  The 
samples  of  sugar  in  which  the  moisture  is  to  be  determined, 
are  weighed  into  metal  dishes  provided  with  a  cover  and 
of  known  weight,  and  these  dishes,  after  being  placed  on 
a  steaming  water-bath,  are  connected  with  the  branch- 
tubes  and  the  air  exhausted. 

Any  convenient  form  of  vacuum  apparatus  may  be  made 
to  serve  equally  as  well,  but  it  is  essential  that  the  temperature 
of  the  liquid  surrounding  the  containing  vessel,  be  kept 
at  100°  C.  or  above  throughout  the  drying. 

Another  method  for  determining  water  in  saccharine 
products,  is  the  method  of  Josse. 

About  2.0  grams  of  the  substance  are  placed  in  a  small 
flat-bottomed  dish,  6  to  10  c.c.  of  water  are  added  and  the 
substance  is  dissolved,  by  aid  of  a  gentle  heat,  if  necessary. 
The  liquid  is  absorbed  by  a  coil  of  paper  about  20  inches 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    117 

long  and  2  inches  wide  and  this  is  dried  for  2  hours  at 
approximately  105°  C. 

After  the  first  weighing  the  coil  should  be  dried  for  an 
additional  hour  and  the  operation  repeated  until  practically 
constant  weight  has  been  attained.  The  temperature  of 
105°  C.  can  be  conveniently  obtained  and  held  by 
drying  in  a  jacketed  air-bath  using  for  the  filling  a  salt 
solution  containing  about  30  parts  of  salt  in  70  parts  of 
water. 

The  following  excellent  method  for  the  determination 
of  water  in  saccharine  products  has  been  devised  by  Paul 
Poetschke. 

Place  10  grams  of  pure  quartz  sand  and  a  short  stirring 
rod  into  a  100  c.c.  beaker.  Dry  thoroughly  at  100°  C., 
cool  in  a  desiccator  and  weigh.  Introduce  about  five  grams 
of  the  sample,  mix  with  the  sand  and  add  gradually,  with 
stirring,  10  c.c.  of  alcohol  (absolute  alcohol  is  preferable). 
Evaporate  to  dryness  on  a  water-bath  (do  not  place  directly 
over  steam,  since  the  material  is  liable  to  bump,  but  stand 
the  beaker  on  the  metal  surface  of  the  bath).  Again  add 
10  c.c.  of  alcohol  and  repeat  the  evaporation  to  dryness  as 
before.  During  the  evaporation  the  beaker  should  be 
protected  against  dust.  After  the  second  portion  of  alcohol 
has  completely  evaporated,  place  the  beaker  in  an  air-bath 
and  dry  for  2J  hours  at  100°  C.  Cool  in  a  desiccator  and 
weigh.  Repeat  the  heating  at  100°  C.  for  one  hour  and  again 
weigh  to  note  whether  drying  is  complete.  Usually  2| 
hours  are  sufficient  for  all  saccharine  products.  The  method 
is  applicable  to  syrups,  honey,  molasses,  maple  syrup,  con- 
fectionery, etc.  Quartz  sand  is  prepared  in  the  usual 
manner  by  digesting  with  strong  hydrochloric  acid,  washing, 
drying  and  igniting.  The  alcohol  used  should  leave  only  an 
inappreciable  residue  on  evaporation. 

A  method  for  approximately  determining  the  amount 
of  water  in  a  sample  of  syrup,  liquor,  or  sweet- water,  is  to 
take  the  Brix  hydrometer  reading  of  the  solution,  and  to 


118  SUGAE  ANALYSIS 

subtract   this    from    100.     The    difference   is   accepted   as 
representing  the  water. 

Example.     Density    of    syrup    in    degrees    Brix,    75.0°. 

100 
Less      75 

25  per  cent  of  water. 

Ash.  Scheibler's  Method.  Weigh  out  2.5  to  5  grams 
of  sample  into  a  platinum  ash-dish.  Moisten  with  eight 
to  ten  drops  of  chemically  pure  cone,  sulphuric  acid,  or 
better,  with  sixteen  to  twenty  drops  of  dilute  sulphuric 
acid  (1  :  1).  Pour  a  little  ether  over  the  contents  of 
the  dish  and  ignite.  This  treatment  yields  a  porous 
carbonized  mass,  and  avoids  in  a  great  measure  the 
danger  of  loss  by  the  assay  mounting  and  creeping  over 
the  sides  of  the  dish.  When  all  gases  have  burned  off, 
place  in  a  platinum  muffle,  or  in  a  Russia  sheet-iron  muffle 
(the  metal  should  be  about  -fa  inch  in  thickness),  and  keep 
the  muffle  at  a  dull-red  heat  until  the  sample  has  been 
turned  completely  to  ash;  cool  and  weigh. 

As  the  addition  of  sulphuric  acid  has  converted  a  num- 
ber of  the  salts  present  in  the  sugar  into  sulphates,  10  per 
cent  is  deducted  from  the  weight  of  the  ash  found  in  order 
to  make  the  results  obtained  by  this  method  harmonize 
with  those  obtained  by  the  method  of  carbonization. 

Example.    Used  2.5  grams  of  sugar. 

Weight  of  dish+ash,    .      .   13.9030 
"  "  .      .   13.8490 

Ash, 0.0540 

Subtract  10  per  cent,    .      .     0.0054 

Total  ash,  =     0.0486 

Total  ash,  =     1 . 944  per  'cent. 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    119 

This  subtraction  of  one  tenth  of  the  weight  of  the  ash 
is  generally  assumed  to  answer  for  beet-sugars,  but  is 
entirely  misleading  where  cane-products  are  analyzed, 
because  the  ash  of  the  latter  possess  a  composition  entirely 
different  from  the  ash  of  the  former.  *  At  present,  however, 
the  subtraction  of  one  tenth  is  still  the  general  practice. 

That  unreliable  results  are  obtained  by  this  method 
of  incineration  with  sulphuric  acid  and  the  subsequent 
subtraction  of  one  tenth  from  the  weight  of  the  sulphated 
ash,  even  when  beet-sugars  are  analyzed,  is  now  generally 
admitted. 

Von  Lippmann  advocates  taking  the  dried-out  sample, 
on  which  the  water  determination  has  been  made,  saturating 
it  with  vaselin-oil  (having  a  boiling  point  of  about  400°), 
and  igniting  the  mixture.  The  carbonized  mass  is  then  to 
be  burned  to  ash  in  a  mixed  current  of  air  and  oxygen. 

Carbonization  Method.  Weigh  out  2.5  to  5.0  grams 
of  the  sample.  Carbonize  at  a  low  heat.  Extract  the 
soluble  salts  from  the  carbonaceous  mass  with  boiling 
water;  ignite  the  residue.  Add  the  ash  obtained  to  the 
aqueous  extract  and  evaporate  to  dryness.  Moisten  with 
ammonium  carbonate,  drive  off  all  ammonia,  cool,  weigh, 
and  report  as  carbonate  ash. 

A  number  of  other  methods  for  determining  ash  in 
sugar  have  been  advocated;  the  use  of  oxalic  acid,  zinc 
oxide,  quartz  sand  and  of  benzoic  acid  has  been  recommended 
for  the  purpose. 

In  the  method  of  Alberti  and  Haempel,  employing 
pure  quartz  sand,  5  grams  of  sugar  are  placed  in  a  platinum 
dish  and  are  intimately  mixed  with  about  6  to  7  grams  of 
coarsely  ground  pure  quartz  sand.  The  mixture  is  ignited 
in  a  platinum  muffle  at  a  moderate  red  heat  and  the  incin- 
eration completed  in  from  one  half  to  an  hour's  time,  accord- 
ing to  the  nature  of  the  sample. 

*Wiechmann,  "Ash  Determinations  in  Raw  Sugars/'  School  of 
Mines  Quarterly,  Vol.  XI. 


120  SUGAR  ANALYSIS 

This  method  depends  on  the  fact  that  when  a  mixture 
of  sugar  and  quartz  (silica),  is  caused  to  undergo  combus- 
tion, this  combustion  is  complete  and  no  carbon  is  left 
unconsumed.  Furthermore  the  organic-acid  salts  are  trans- 
formed into  silicates  and  not  into  carbonates,  and  the  sul- 
phates and  alkaline  chlorides  originally  present  in  the  sugars, 
are  not  decomposed  by  the  silicic  acid  at  the  temperature 
at  which  the  operation  is  carried  out.  This  method  has 
been  extensively  tested  abroad,  and  the  results  are  reported 
as  satisfactory,  provided  that  pure  quartz  sand  be  employed. 

The  benzoic  acid  method,  devised  by  Boyer  is  described 
as  follows:  *  "  The  benzoic  acid  is  dissolved  in  alcohol 
of  90  per  cent,  25  grams  of  the  acid  to  100  c.c.  of  alcohol; 
5  grams  of  the  sugar  are  weighed  in  a  capsule  and  moistened 
with  1  c.c.  of  water.  The  capsule  is  heated  slowly  in  order 
to  caramelize  the  sugar  without  carbonizing  it;  2  c.c. 
of  the  benzoic-acid  solution  are  next  added,  and  the  capsule 
warmed  until  all  the  alcohol  is  evaporated;  the  tempera- 
ture is  then  raised  until  the  sugar  is  converted  into  carbon. 
The  decomposing  benzoic  acid  produces  abundant  vapors 
which  render  the  mass  extremely  porous,  especially  if  a 
circular  motion  is  imparted  to  the  capsule.  The  slow 
heating  is  continued  until  all  the  benzoic  acid  is  volatilized. 

"  The  carbon  obtained  is  voluminous  and  of  a  brilliant 
black  color.  The  incineration  is  accomplished  in  a  muffle 
at  a  low  red  heat.  The  capsule  should  be  weighed  quickly 
when  taken  from  the  desiccator,  in  order  to  avoid  the  absorp- 
tion of  water  by  the  alkaline  carbonates.  Ammonium 
benzoate  may  be  employed  instead  of  benzoic  acid,  and  the 
analyst  should  previously  assure  himself  that  neither  the 
acid  nor  the  ammonia  salt  leaves  a  residue  on  incinera- 
tion. In  addition  to  giving  the  mineral  matters  directly, 
this  method  permits  the  determination  of  their  composi- 
tion also,  a  matter  of  no  small  importance." 

*  U.  S.  Dept.  of  Agriculture,  Division  of  Chemistry,  Bui.  No.  38, 
1893. 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    121 

Analysis  of  Sugar- Ash.  Dissolve  10  grams  of  the 
sugar  in  hot  water  and  filter;  *  wash  the  residue  thoroughly 
with  boiling  water  and  evaporate  the  nitrate  and  the  wash- 
ings to  dryness.  Carefully  carbonize  the  mass,  and  then 
extract  the  same  with  boiling  water  until  nitrate  of  silver 
no  longer  gives  the  reaction  for  chlorine.  Evaporate  the 
solution  to  small  bulk.  The  residue  must  be  dried,  ignited, 
and  weighed.  This  weight  is  noted  as  insoluble  ash.  The 
solution  and  the  ash  obtained  are  then  combined,  hydro- 
chloric acid  is  added,  and  the  solution  evaporated  to  dry- 
ness.  All  the  chlorine  is  then  driven  off,  the  residue  is 
taken  up  with  water  and  a  little  hydrochloric  acid,  and 
filtered.  The  insoluble  residue  on  the  filter  is  thoroughly 
washed,  and  the  washings  are  added  to  the  filtrate.  This 
residue  is  silica.  To  the  filtrate  ammonic  hydrate  is  added, 
and  the  solution  is  boiled  and  filtered;  the  residue,  iron 
and  alumina,  must  be  thoroughly  washed,  and  the  washings 
added  to  the  filtrate. 

To  this  ammonium  oxalate  is  added,  and  the  whole 
is  evaporated  to  dryness.  The  ammonia  is  burned  off, 
and  the  oxalates  are  changed  to  carbonates  by  adding  a 
little  ammonium  carbonate,  and  again  driving  off  the 
ammonia. 

The  mass  is  then  taken  up  with  water,  filtered,  washed, 
and  the  washings  added  to  the  filtrate.  The  residue  con- 
sists of  the  carbonates  of  calcium  and  magnesium.  The 
filtrate  is  evaporated  to  small  bulk,  ammonium  carbonate 
is  added,  and  the  evaporation  is  then  continued  to  dryness, 
the  ammonia  is  cautiously  driven  off,  and  the  residue 
weighed.  This  gives  the  alkalies  in  the  form  of  carbonates, 
and  this  weight  added  to  the  weight  of  the  insoluble  ash 
previously  determined,  represents  the  total  carbonate  ash. 

*  This  should  be  done  in  every  case  so  as  to  have  all  the  analyses 
made  under  the  same  conditions;  in  most  instances  it  will  be  impera- 
tive, for  the  inorganic  suspended  impurities  (sand,  clay,  etc.)  in  a 
Sample  of  cane-sugar  often  weigh  more  than  the  total  sugar-ash. 


122  SUGAR  ANALYSIS 

Suspended  Impurities.  It  is  often  necessary  to  de- 
termine the  share  of  work  done  in  nitration  respectively 
by  the  bag-filters  and  the  bone-black. 

The  former,  of  course,  remove  only  the  mechanically 
suspended  impurities,  or  at  least  the  greater  part  of  them, 
and  leave  to  the  bone-black  the  rest  of  the  work  to  be 
accomplished. 

The  suspended  impurities  are  both  mineral  and  organic; 
their  determination  is  effected  in  the  following  manner: 

Dissolve  from  2.5  to  10  grams  of  the  sample  in  hot 
water.  Pour  on  a  filter  paper  which  has  previously  been 
dried  and  weighed  between  watch  glasses,  and  wash  with 
boiling  water  until  all  of  the  sugar  has  been  removed. 
This  is  most  conveniently  done  by  the  aid  of  a  vacuum- 
pump.  Then  dry  filter  and  contents  to  constant  weight, 
and  weigh  as  before  between  watch  glasses.  The  increase 
in  weight  over  the  previous  weight,  represents  the  total 
suspended  impurities.  Ignite  the  filter  and  contents  in  a 
platinum  crucible,  and  record  the  weight  of  the  ash  as 
mineral  or  inorganic  suspended  impurities;  the  difference 
between  the  total  suspended  impurities  and  this  figure 
gives  the  organic  suspended  impurities. 

An  ash  determination  made  as  previously  described 
represents  the  mineral  matter  contained  in  the  sugar,  in 
the  form  of  salts,  etc.,  as  well  as  the  mineral  matter  mechan- 
ically suspended,  and  which  latter,  the  bag-filters  are  sup- 
posed to  remove. 

The  inorganic  suspended  impurities  when  subtracted 
from  the  total  ash  show  the  "  soluble  "  ash,  the  more  or  less 
complete  removal  of  which  is  expected  of  the  bone-black. 

Example.     Used  2.5  grams  of  raw  sugar. 
Weight  of  watch  glasses + filter + total  suspended 

impurities,         22.5071 

Weight  of  watch  glasses + filter, 22.5000 

Total  suspended  impurities,       '.      .       0.0071 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    123 

Weight  of  crucible+ash  of  fi It er-f-  inorganic  sus- 
pended impurities,     13.20020 

Weight  of  crucible, 13.20000 

Ash  of  filter + inorganic  susp.  impurities,  .      .      .       0.00020 
Ash  of  filter, 0.00008 

Inorganic  susp.  impurities,        .      .       0.00012 

Total  suspended  impurities,       0 . 00710  =  0 . 2840   per    cent. 
Inorganic  "  "  0.00012  =  0.0048         li 

Organic  (l  "  0.00698  =  0.2792 

Total  ash  (previously  determined),    .      .   0.5040   per    cent. 
Inorganic  suspended  impurities,    .      .      .   0 . 0048 

Soluble  ash, 0.4992 

Woody  Fiber.  About  20  to  25  grams  of  the  sample, 
in  as  finely  divided  a  state  as  possible,  are  placed  in  a  flask 
or  beaker,  into  which  cold  water  is  poured.  The  water, 
after  having  been  in  contact  with  the  chips  or  shavings 
from  20  to  30  minutes,  is  decanted  carefully,  in  order  to 
avoid  any  loss  of  the  weighed  sample.  This  treatment 
with  cold  water  is  repeated  two  or  three  times,  and  is  then 
followed  by  a  similar  treatment  with  hot  water;  finally, 
the  sample  is  boiled  several  times,  fresh  water  being  taken 
for  each  treatment,  and  the  treatment  continued  until  all 
the  soluble  material  has  been  washed  out.  Sometimes 
this  is  followed  by  washings  with  alcohol  and  ether. 

The  sample  is  then  transferred  to  a  weighed  filter, 
preferably  made  of  asbestos,  and  gradually  dried  to  con- 
stant weight.  If  dried  in  the  air-bath,  a  temperature  of 
110°  C.  should  not  be  exceeded.  If  the  sample  can  be 
dried  in  vacuo,  and  subsequently  weighed  in  a  covered 
dish  or  capsule,  all  danger  of  oxidation  and  absorption 
of  moisture  are  avoided. 

The  increase  in  weight  which  *s  noted  of  course 
represents  the  woody  fiber. 


124  SUGAR  ANALYSIS 

Organic  Non-Sugar.  In  regular  technical  analyses  the 
organic  matter  not  sugar,  raffinose,  or  invert  sugar  is  not 
determined.  It  is  assumed  to  be  represented  by  the  differ- 
ence between  100  and  the  constituents  determined,  viz., 
sucrose,  raffinose,  invert  sugar,  water,  and  ash.  This 
difference  is  frequently  recorded  as  "non-ascertained," 
or  "undetermined  matter." 

Herzfeld  has  suggested  that  the  "  total  non-sugar" 
could  be  determined  by  ascertaining  the  sucrose  and  the 
dry-substance,  and  subtracting  the  former  from  the  latter. 

If  instead  of  doing  this,  the  sucrose  plus  the  ash  be 
subtracted  from  the  dry  substance,  the  remainder  may  be 
regarded  as  "  organic  non-sugar."  In  that  case,  of  course 
the  invert  sugar  and  the  raffinose  would  also  be  embraced 
under  the  heading  "  organic  non-sugar,"  unless  these 
were  separately  determined. 

There  are  several  methods  for  the  direct  determina- 
tion of  this  organic  matter,  but  the  results  which  they  yield 
are  of  value  chiefly  for  comparative  purposes.  The  fol- 
lowing method  is  perhaps  the  most  satisfactory: 

Dissolve  10  to  20  grams  of  raw  sugar  in  warm  water. 
Add  basic  acetate  of  lead  solution  in  excess.  Warm  for 
a  short  time  and  filter.  Wash  the  precipitate  thoroughly; 
then  suspend  it  in  water  and  pass  in  sulphuretted  hydrogen 
until  all  the  lead  is  precipitated  as  sulphide.  Filter  out 
the  sulphide  of  lead,  wash  thoroughly,  and  evaporate  the 
filtrate  and  washings  to  dryness  (constant  weight),  in  a 
dish  previously  weighed.  The  temperature  at  which 
the  drying  is  done,  must  not  exceed  100°  C. 

Example.     Used  10  grams  of  raw  sugar. 

Weight  of  dish  and  organic  matter,       ....     17.0973 
dish, 17.0482 

Organic  matter, 0 . 0491 

Organic  matter  =  0.491  per  cent. 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    125 

Organic  Acids.  Determination  of  some  organic  acids — 
non-volatile  and  volatile,  can  be  approximately  effected 
by  the  following  scheme.* 

APPROXIMATE     DETERMINATION    OF    ORGANIC    ACIDS, 
NON-VOLATILE   AND   VOLATILE 


Non-volatile  Acids. 

Volatile  Acids. 

A.  Precipitation    by    neu- 
tral acetate  of  lead. 

B.     Precipi-      C.     Precipita- 
tation  by  basic  tlon    by    ammo- 

D.  Not     precipitated     by 
acetate     of     lead:      formic. 

Oxalic,  citric,  tartaric,  and 

acetate  of  lead. 

niacal       acetate;  acetic,  lactic,  propionic,  and 

malic     acids.     Incompletely: 

Pectic.  para- 

of      lead.       As-l  butyric  acids. 

pecuc,      parapectic,      glucic, 

pectic,    giucic, 

par  tic  and  met- 

melassinic,    ulmlc,    and    suc- 

melassinic,   ul- 

apectic  acids. 

_^__ 

c.nic  acids. 

mic,   and  suc- 

50    grams   of    the   sample 
are     dissolved     in     distilled 

Parapectin,  In- 
completely: as- 

The     filtrate 

50     grams    of    the    sam- 
ple to  be  examined  (in  case 
of    juices    a    larger    amount 

water  and  made  slightly  acid 
with  acetic  acid.     The  solu- 
tion  Is   boiled   to   expel   uie 

\>  a  r  t  i  c     and  obtained      from 
iii  e  tape  cticthe      precipita- 
acids,     anu  tion    with    basic 

must  be  taken;   thick  syrup 
must  be  diluted)  ,  are  strongly 
acidified     with     dilute     sul- 

carbonic  acid,    and    neutral- 
ized   with    sodium    hydrate 
(free    from    carbonic    acid). 

pectin. 

acetate    of    lead 
is     mixed     with 
several     cubic 

phuric  acid.     All  the  chlorine 
which    has    been    previously 
determined  volumetrically  In 

A    slight    excess    of    neutral 
acetate  of  lead  is  added,  and      To    the    fll- 
Uigested  for  one  hour.     The  trate  from  the 
residue   Is   placed   on   a   dry  lead  salts  pre- 
and    weighed    filter,    and    is  cipitated      by 
washed  with  boiled  distilled  neutral       ace- 
water     until     the     washings  tate    of    lead, 
give    no  longer   the  reaction  there  is  added 

centimeters       ol 
an     ammoniacal 
acetate    of    lead 
solution.          Al- 
low to  stand  for 
twelve        hours. 
Filter,    allow    to 
drain     off,     and 

a  separate  sample,  Is  precip- 
itated    by     a     standardized 
sulphate    of    silver    solution. 
The  filtrate  from  the  argentic 
chloride     Is     distilled     until 
acid    fumes    no    longer    pass 
over.     This  distillate  is  then 
mixed    with    a    solution    of 

for  lead.     (For  treatment  of  a  slight  excess 
the  filtrate,  see  B.)                   \of    basic  ,ace- 
The    precipitate    contains  tate    of    lead, 

wash  once   with 
distilled       water 
to  which  a  little 

barium   hydrate,   any  excess 
of  this  reagent  Is  precipitated 
by    carbonic    acid,    and    the 

the  lead  salts  of    the  above 

and    tue    pre- 

ammoniacal  ace- 

solution    filtered.     The     fil- 

named   acids,    and     besides  cipitate     III  - 
sulphate    and    phosphate    ofteredout.  (For 
lead,  if  the  sample  examined  nitrate,  see  C.) 

tate  of  lead  has 
been  added.  The 
precipitate,  dried 

trate  Is  evaporated  to   dry- 
ness  at  110°  C.  in  a  weighed 
platinum    capsule:     the   res- 

contained      sulphates       and 

rne  precipi- 

and  weighed,    Is 

idue    represents    the    weight 

phosphates.     The  filter  with 

tate   Is   placed 

treated     as     de- 

of  the  organic  acid  salts  of 

Its  contents  Is  dried  at  110°  on  a  dried  and  scribed   under 
C.,   and  weighed.     The  pre-i  weighed   filter,  A  and  B. 
cipitate  is  removed,  the  filter  then     washed.      Not  e.  —  The 
Is  burned  In  a  weighed  por-  dried  atl     °  C.I  ammoniacal  ace- 

barium,  which  are  determined 
as  sulphates  or  carbonates. 
If    nitrates    were    present 
In     the     sample     analyzed, 

, 
tate    is    again    added,     and  A  part  is  incln-  must    be    added  barium      nitrate      In 


gradually  case    the    nitric'  acid 


heated  to  dull  redness. '  erated  as  In  A  J  only 

To  facilitate  the   combus-  and  the  weight  and 

tlon    of    tha    carbon,    small  of  the  organic  amounts        f  o  r  of  the 
doses  of   ammonium   nitrate  acids  ^      deter-:  without     this  culated 


the  residue  contains  also 
that 
must 


mall  be    determined,    the    weight 


repeatedly   added,   great  mined  by 
!  being  taken  to  prevent  .'  erence. 


are 

loss  b"y"splttingT  After  "cool-  t  h  e  r _e 
Ing,  the  crucible  Is  weighed,  scribed. 
The  weight  of  the  contents 
of  the  crucible  subtracted 
from  that  of  the  precipitate 
dried  at  110°  C.  represents 
the  weight  of  the  organic 
acids,  because  the  sulphate 
and  phosphate  of  lead  are 
not  altered  by  the  ignition. 


dif-  precaution 


barium    nitrate    cal- 
from     the     result. 


and    this    value    subtracted 


as  apt    to    precipi-  from     the     weight     of     the 
de-  tate   sugar,    and  organic  acid  salts  of  barium 


termination  o  f 
the  acids  sought 
for,  becomes  very 
difficult. 


*  Translated  by  the  author  from  the  French,  E.  Langier-Bittman's 
arrangement. 


126  SUGAR  ANALYSIS 

NITROGENOUS  SUBSTANCES.    THE  ABSOLUTE  OR  CUPRIC 
OX  ID  METHOD.* 

[Applicable  to  all  nitrogen  determinations.] 
'The  apparatus  and  reagents  needed  are  as  follows: 

^APPARATUS. 

Combustion  tube  of  best  hard  Bohemian  glass,  about 
66  cm.  long  and  12.7  m.m.  internal  diameter. 

Azotometer  of  at  least  100  c.c.  capacity,  accurately  cali- 
brated. 

Sprengel  mercury  air  pump. 

Small  paper  scoop,  easily  made  from  stiff  writing  paper. 

REAGENTS. 

Coarse  cupric  oxid  or  wire  form.  To  be  ignited  and 
cooled  before  using. 

Fine  cupric  oxid.  Prepared  by  pounding  ordinary 
cupric  oxid  in  a  mortar. 

Metallic  copper.  Granulated  copper,  or  fine  copper 
gauze,  reduced  and  cooled  in  a  current  of  hydrogen. 

Sodium  bicarbonate.     Free  from  organic  matter. 

Caustic  potash  solution.  Make  a  supersaturated  solu- 
tion of  caustic  potash  in  hot  water.  When  absorption  of 
carbonic  acid  ceases  to  be  prompt,  the  solution  must  be 
discarded. 

MANIPULATION. 

Filling  the  tube.  Of  ordinary  commercial  fertilizers 
take  1  to  2  grams  for  analysis.  In  the  case  of  highly  nitro- 
genized  substances  the  amount  to  be  taken  must  be  regu- 
lated by  the  amount  of  nitrogen  estimated  to  be  present. 

*  Reprinted  from  Bulletin  No.  38,  U.  S.  Dept.  of  Agriculture, 
Division  of  Chemistry. 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    127 

Fill  the  tube  as  follows:  (1)  About  5  cm.  of  coarse  cupric 
oxid.  (2)  Place  on  the  small  paper  scoop  enough  of  the 
fine  cupric  oxid  to  fill,  after  having  been  mixed  with  the 
substance  to  be  analyzed,  about  10  cm.  of  the  tube;  pour 
on  this  the  substance,  rinsing  the  watch  glass  with  a  little 
of  the  fine  oxid,  and  mix  thoroughly  with  a  spatula;  pour 
into  the  tube,  rinsing  the  scoop  with  a  little  fine  oxid.  (3) 
About  30  cm.  of  coarse  cupric  oxid.  (4)  About  7  cm.  of 
metallic  copper.  (5)  About  6  cm.  of  coarse  cupric  oxid 
(anterior  layer).  (6)  A  small  plug  of  asbestos.  (7)  0.8 
to  1  gram  of  sodium  bicarbonate.  (8)  A  large,  loose  plug 
of  asbestos;  place  the  tube  in  the  furnace,  leaving  about 
2.5  cm.  of  it  projecting;  connect  with  the  pump  by  a  rubber 
stopper  smeared  with  glycerol,  taking  care  to  make  the 
connection  perfectly  tight. 

OPERATION. 

Exhaust  the  air  from  the  tube  by  means  of  the  pump. 
When  a  vacuum  has  been  obtained  allow  the  flow  of  mer- 
cury to  continue;  light  the  gas  under  that  part  of  the 
tube  containing  the  metallic  copper,  the  anterior  layer  of 
cupric  oxid  (see  5th  above),  and  the  sodium  bicarbonate. 
As  soon  as  the  vacuum  is  destroyed  and  the  apparatus 
filled  with  carbonic  acid,  shut  off  the  flow  of  mercury  and 
at  once  introduce  the  delivery  tube  of  the  pump  into  the 
receiving  arm  of  the  azotometer  just  below  the  surface 
of  the  mercury  seal,  so  that  the  escaping  bubbles  will  pass 
into  the  air  and  not  into  the  tube,  thus  avoiding  the  useless 
saturation  of  the  caustic-potash  solution. 

When  the  flow  of  carbonic  acid  has  very  nearly  or  com- 
pletely ceased,  pass  the  delivery  tube  down  into  the  re- 
ceiving arm,  so  that  the  bubbles  will  escape  into  the  azotom- 
eter. Light  the  gas  under  the  30  cm.  layer  of  oxid,  heat 
gently  for  a  few  moments  to  drive  out  any  moisture  that 
may  be  present,  and  'bring  to  red  heat.  Heat  gradually 


128  SUGAR  ANALYSIS 

the  mixture  cf  substance  and  oxid,  lighting  one  jet  at  a  time. 
Avoid  a  too  rapid  evolution  of  bubbles  which  should  be 
allowed  to  escape  at  the  rate  of  about  one  per  second  or 
a  little  faster. 

When  the  jets  under  the  mixture  have  all  been  turned 
on,  light  the  gas  under  the  layer  of  oxid  at  the  end  of  the 
tube.  When  the  evolution  -of  gas  has  ceased,  turn  out 
all  the  lights  except  those  under  the  metallic  copper  and 
anterior  layer  of  oxid,  and  allow  to  cool  for  a  few  moments. 
Exhaust  with  the  pump  and  remove  the  azotometer  before 
the  flow  of  mercury  is  stopped.  Break  the  connection  of 
the  tube  with  the  pump,  stop  the  flow  of  mercury,  and 
extinguish  the  lights.  Allow  the  azotometer  to  stand  for  at 
least  an  houf^or  cool  with  a  stream  of  water  until  a  per- 
manent volume  and  a  temperature  have  been  reached. 

Adjust  accurately  the  level  of  the  KOH  solution  in  bulb 
to  that  in  the  azotometer;  note  the  volume  of  gas,  tem- 
perature, and  height  of  barometer;  make  calculation  as 
usual,  or  read  results  from  tables. 

THE  KJELDAHL  METHOD 

[Not  applicable  in  presence  of  nitrates.] 

REAGENTS. 

(1)  Add.  (a)  Standard  hydrochloric  acid,  the  absolute 
strength  of  which  has  been  determined  by  precipitating 
with  silver  nitrate  and  weighing  the  silver  chlorid  as  follows : 

To  any  convenient  quantity  of  the  acid  to  be  standardized : 
Add  solution  of  silver  nitrate  in  slight  excess,  and  2  c.c. 
pure  nitric  acid,  specific  gravity,  1.2.  Heat  to  boiling 
point,  and  keep  at  this  temperature  for  some  minutes 
without  allowing  violent  ebullition,  and  with  constant 
stirring,  until  the  precipitate  assumes  the  granular  form. 
Allow  to  cool  somewhat,  and  then  pass  the  fluid  through 
the  asbestos.  Wash  the  precipitate  by  decantation,  with 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    129 

200  c.c.  of  very  hot  water,  to  which  has  been  added  8  c.c. 
nitric  acid  and  2  c.c.  dilute  solution  of  silver  nitrate  con- 
taining 1  gram  of  the  salt  in  100  c.c.  of  water.  The  washing 
by  decant  ation  is  performed  by  adding  the  hot  mixture  in 
small  quantities  at  a  time,  and  beating  up  the  precipitate 
well  with  a  thin  glass  rod  after  each  addition.  The  pump 
is  kept  in  action  all  the  time,  but  to  keep  out  dust  during 
the  washing  the  cover  is  only  removed  from  the  crucible 
when  the  fluid  is  to  be  added. 

Put  the  capsule  and  precipitate  aside,  return  the  washings 
once  through  the  asbestos  so  as  to  obtain  them  quite  clear, 
remove  them  from  the  filter,  and  set  aside  to  recover  excess 
of  silver.  Rinse  the  receiver  and  complete  the  washing 
of  the  precipitate  with  about  200  c.c.  of  cold  water.  Half 
of  this  is  used  to  wash  by  decantation  and  the  remainder 
to  transfer  the  precipitate  to  the  crucible  with  the  aid  of  a 
trimmed  feather.  Finish  washing  in  the  crucible,  the  lumps 
of  silver  chlorid  being  broken  down  with  the  glass  rod. 
Remove  the  second  nitrate  from  the  receiver  and  pass 
about  20  c.c.  of  98  per  cent  alcohol  through  the  precipitate. 
Dry  at  140°  to  150°.  Exposure  for  half  an  hour  is  found 
more  than  sufficient,  at  this  temperature,  to  dry  the  pre- 
cipitate thoroughly. 

Or  (b)  standard  sulphuric  acid  the  absolute  strength  of 
which  has  been  determined  by  precipitation  with  barium 
chlorid  and  weighing  the  resulting  barium  sulphate. 

For  ordinary  work,  half  normal  acid  is  recommended; 
i.e.,  acid  containing  18.2285  grams  of  hydrochloric  acid 
or  24.5185  grams  sulphuric  acid  to  the  liter;  for  work  in 
determining  very  small  amounts  of  nitrogen,  one-tenth 
normal  acid  is  recommended.  In  titrating  mineral  acids 
against  ammonia  solutions,  use  cochineal  as  indicator. 

(2)  Standard  ammonia,  the  strength  of  which,  relative 
to  the  acid,  has  been  accurately  determined.  One-tenth 
normal  ammonia  solution,  i.e.,  containing  1.7051  grams 
of  ammonia  to  the  liter,  is  recommended  for  accurate  work. 


130  SUGAR  ANALYSIS 

(3)  Sulphuric    add,    specific    gravity    1.84,    free    from 
nitrates  and  also  from  ammonium  sulphate,  which  is  some- 
times added  in  the  process  of  manufacture  to  destroy  oxids 
of  nitrogen. 

(4)  Metallic  mercury  or  mercuric  oxid,  prepared  in  the 
wet  way.     That  prepared  from  mercuric  nitrate  can  not 
be  safely  used. 

(5)  Potassium  permanganate  finely  pulverized. 

(6)  Granulated  zinc,  pumice  stone,  or  0.5  gram  of  zinc 
dust  are  to  be  added  to  the  contents  of  the  flasks  in  dis- 
tillation, when  found  necessary,  in  order  to  prevent  bump- 
ing. 

(7)  Potassium    sulphid.     A    solution    of    40    grams    of 
commercial  potassium  sulphid  in  1  liter  of  water. 

(8)  Soda.     A    saturated    solution    of    sodium    hydrate 
free  from  nitrates. 

(9)  Indicator.     Solution  of  cochineal  prepared  as  follows : 
Tincture  of  cochineal  is  prepared  by  digesting  and  frequently 
agitating  3  grams  of  pulverized  cochineal  in  a  mixture  of 
50  c.c.  of  strong  alcohol  with  200  c.c.  of  distilled  water,  at 
ordinary  temperatures,   for  a  day  or  two.     The  solution 
is  decanted  or  filtered  through  Swedish  paper. 

APPARATUS. 

(1)  Kjeldahl  digestion  flasks  of  hard,  moderately  thick, 
well-annealed  glass.      These   flasks  are  about  22  cm.  long, 
with   a   round,   pear-shaped   bottom,   having   a   maximum 
diameter  of  6  cm.,  and  tapering  out  gradually  in  a  long  neck, 
which  is  2  cm.  in  diameter  at  the  narrowest  part,  and  flared 
a  little  at  the  edge.     The  total  capacity  is  225  to  250  c.c. 

(2)  Distillation  flasks  of    ordinary    shape,   of    550    c.c. 
capacity,  or  preferably  flasks  of  the  same  capacity,  of  pear- 
shaped  bottom,  of  well-annealed  glass,  for  both  digestion 
and  distillation,  fitted  with  a  rubber  stopper  and  a  bulb 
tube  above  to  prevent  the  possibility  of  sodium  hydrate 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    131 

being  carried  over  mechanically  during  distillation.  The 
bulbs  are  about  3  cm.  in  diameter,  the  tubes  being  of  the 
same  diameter  as  the  condenser  and  cut  off  obliquely  at 
the  lower  end.  This  is  adjusted  to  the  tube  of  the  con- 
denser by  a  rubber  tube. 

MANIPULATION. 

(1)  The  digestion.     0.7  to  0.8   gram  of  the  substance 
to  be  analyzed,  according  to  its  proportion  of  nitrogen, 
is  brought  into  a  digestion  flask  with  approximately  0.7 
gram  of  mercuric  oxid  or  its  equivalent  in  metallic  mercury 
and  22  c.c.  of  sulphuric  acid.     The  flask  is  placed  in  an 
inclined  position,  and  heated  below  the  boiling  point  of  the 
acid  for  from  five  to  fifteen  minutes  or  until  frothing  has 
ceased.     If  the  mixture  froths  badly,  a  small  piece  of  paraffin 
may  be  added  to  prevent  it.     The  heat  is  then  raised  until 
the  acid  boils  briskly.     No  further  attention  is  required 
till  the  contents  of  the  flask  have  become  a  clear  liquid, 
which  is  colorless  or  at  least  has  only  a  very  pale  straw  color. 
The  flask  is  then  removed  from  the  frame,  held  upright, 
and  while  still  hot  potassium  permanganate  is  dropped  in 
carefully  and  in  small  quantities  at  a  time  till,  after  shaking, 
the  liquid  remains  of  a  green  or  purple  color. 

(2)  The  distillation.     After  cooling,  the  contents  of  the 
flask  are  transferred  to  the  distilling  flask  with  about  200 
c.c.  of  water,  with  a  few  pieces  of  granulated  zinc,  pumice 
stone,  or  0.5  gram  of  zinc  dust  when  found  necessary  to  keep 
the  contents  of  the  flask  from  bumping,  and  25  c.c.  of  potas- 
sium sulphid  solution   are   added,  shaking  the  flask  to  mix 
its  contents.     Next   add  50   c.c.   of  the   soda  solution,   or 
sufficient  to  make  the  reaction  strongly  alkaline,  pouring 
it  down  the  side  of  the  flask  so  that  it  does  not  mix  at  once 
with  acid  solution.     Connect  the  flask  with  the  condenser, 
mix  the  contents  by  shaking  and  distil  until  all  ammonia 
has  passed  over  into  the  standard  acid.     The  first  150  c.c. 


132  SUGAB  ANALYSIS 

of  the  distillate  will  generally  contain  all  the  ammonia. 
This  operation  usually  requires  from  forty  minutes  to  one 
hour  and  a  half.  The  distillate  is  then  titrated  with  standard 
ammonia. 

The  use  of  mercuric  oxid  in  this  operation  greatly  shortens 
the  time  necessary  for  digestion,  which  is  rarely  over  an 
hour  and  a  half  in  case  of  substances  most  difficult  to  oxidize, 
and  is  more  commonly  less  than  an  hour.  In  most  cases  the 
use  of  potassium  permanganate  is  quite  unnecessary,  but 
it  is  believed  that  in  exceptional  cases  it  is  required  for 
complete  oxidation,  and  in  view  of  the  uncertainty  it  is 
always  used.  The  potassium  sulphid  removes  all  the 
mercury  from  the  solution,  and  so  prevents  the  formation 
of  mercur-ammonium  compounds  which  are  not  com- 
pletely decomposed  by  soda  solution.  The  addition  of 
zinc  gives  rise  to  an  evolution  of  hydrogen  and  prevents 
violent  bumping.  Previous  to  use  the  reagents  should  be 
tested  by  a  blank  experiment  with  sugar,  which  will  partially 
reduce  any  nitrates  that  are  present,  which  might  otherwise 
escape  notice." 

The  Gunning  Kjeldahl  method  is  frequently  employed  for 
the  determination  of  nitrogenous  substances  in  cane  juices. 

Use  a  flask  made  of  strong,  hard  glass  having  a  capacity 
of  about  350  c.c. 

25  c.c.  of  the  sugar  solution  (cane  juice)  concentrated 
to  a  small  volume,  are  introduced  into  the  flask  and  the 
same  amount  of  concentrated  sulphuric  acid  is  added. 
12.0  grams  of  finely  powdered  potassium  sulphate  are 
then  gradually  added  arid  flask  with  contents  very  gently 
heated  until  the  frothing  ceases.  Then  the  temperature 
is  raised  and  the  solution  boiled  until  it  becomes  colorless. 

The  flask  is  then  cooled,  its  contents  transferred  to  a 
liter  flask,  the  solution  made  distinctly  alkaline  with  sodium 
hydrate  and  all  of  the  ammonia  is  distilled  into  a  small 

71 

flask  containing  50  c.c.  of  a         sulphuric  acid   solution. 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    133 

Cochineal  is  preferably  used  as  an  indicator  and  any 
remaining  acid  which  has  not  been  neutralized  by  the 

TL 

ammonia  distilled  over,  is  determined  by  titration  with  -^ 

ammonia  hydrate  solution.  Of  course  the  sulphuric  acid 
used  must  be  entirely  free  from  nitrogen,  if  not,  a  determina- 
tion of  the  same  must  be  made  and  the  amount  found  must 
be  allowed  for  in  all  determinations  made. 

Amides  and  Albumenoid  Nitrogen.* 

Non-Nitrogenous  Substances.  The  determination  of 
n^n-nitrogenous  organic  substances  is  effected  by  aid  of 
basic  and  neutral  acetate  of  lead  and  alcohol  (pectin  and 
parapectin),  by  the  successive  use  of  water,  alkalies,  acids, 
alcohol,  and  ether  (cellulose),  by  treatment  with  ether 
(fats,  essential  oils),  by  the  aid  of  yeast  fermentation, 
and  alcohol  (isolation  of  mannite). 

Cellulose.  To  make  this  determination,  place  10  grams 
of  the  sample,  30  to  40  grams  of  pure  potassium  hydrate, 
and  about  30  to  40  c.c.  of  water  into  a  glass  retort.  Close 
the  retort  by  a  glass  stopper,  place  in  an  oil-bath,  provided 
with  a  thermometer,  and  heat  up  gradually.  At  about 
140°  C.  the  solution  will  commence  to  boil  and  foam  con- 
siderably. Increase  the  temperature  to  about  180°  C.,  and 
continue  heating  for  about  one  hour.  When  the  contents 
of  the  retort  cease  foaming,  become  quiet,  and  begin  to 
turn  dry,  the  end  of  the  reaction  has  been  reached. 

Remove  the  retort  from  the  oil-bath,  and  after  cooling 
to  about  80°  C.,  add  hot  water  and  rinse  the  contents  of  the 
retort  carefully  first  with  hot  and  then  with  cold  water, 
into  a  beaker. 

After  cooling,  acidify  with  dilute  sulphuric  acid;  this 
acid  will  precipitate  the  particles  of  cellulose  which  have 
been  kept  in  suspension  in  the  strong  alkaline  solution. 

*  Confer:  Bulletin  No.  107,  Bureau  of  Chemistry  U.  S.  Dept.  of 
Agriculture,  or  abstracts  thereof  in  Noel  Deer,  Cane  Sugar,  Altrincham, 
1911,  pp.  481-482.  *f 


134  SUGAR  ANALYSIS 

Then,  with  very  dilute  sodium  hydrate,  produce  anew  a 
faintly  alkaline  reaction,  so  that  all  of  the  precipitated 
substances,  excepting  the  cellulose,  may  be  again  brought 
into  solution. 

The  residue  is  then  transferred  to  a  weighed  filtering 
tube  provided  with  a  finely  perforated  platinum  cone 
and  washed  out  thoroughly,  first  with  hot  water,  and 
then  with  cold.  Drying  is  effected  on  a  water-bath,  and 
the  filter  with  its  contents  weighed. 

The  residue  is  then  removed  from  the  filter,  ignited, 
and  the  weight  of  the  ash  found  subtracted  from  the  value 
previously  obtained.  The  difference  in  weight  represents 
pure  cellulose. 

Gums.  The  gummy  substances  occurring,  for  instance, 
in  cane-juices  are  insoluble  in  alcohol  and  their  determina- 
tion is  based  on  this  property. 

Concentrate  100  c.c.  of  juice  to  20  c.c.  Pour  these 
into  100  c.c.  of  alcohol  (90%  strength),  which  has  been 
acidified  with  1  c.c.  of  hydrochloric  acid. 

Allow  the  precipitate  to  settle,  wash  with  strong  alcohol, 
first  by  decantation,  and  then  on  a  weighed  filter.  Dry 
to  constant  weight  and  note  weight  of  filter  with  its  con- 
tents. Incinerate,  and  weigh  the  mineral  matter  (ash) 
remaining. 

The  first  weight,  after  allowing  for  the  tare  of  the  filter 
paper,  represents  the  weight  of  the  gums  plus  the  weight 
of  the  ash  in  the  juice.  The  second  weight,  after  allowing 
for  the  weight  of  the  crucible,  is  the  weight  of  the  ash. 
This  value  subtracted  from  the  combined  weight  of  the 
gums  and  the  ash,  is  the  weight  of  the  gums  sought  for. 

Alkalinity  of  Sugars.  Indicators.  Indicators  are  chem- 
ical compounds  which  exhibit  markedly  different  colors 
according  to  their  being  placed  in  acid  or  in  alkaline  solu- 
tions. 

A  large  number  of  indicators  have  been  suggested  for, 
tried  in,  the  sugar  industry,  but,  for  various  reasons, 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    135 

most  of  them  have  been  discarded  and  to-day  phenol 
phthalein,  litmus,  and  rosolic  acid,  (corallin)  are  about  the 
only  indicators  that  find  practical  application  in  sugar 
work. 

These  indicators  exhibit  the  following  colors: 


In  Acid  Solution. 

In  Alkaline  Solution. 

Phenol  phthalein  
Litmus 

Colorless 
Red 

Red 
Blue 

Rosolic  acid  (Corallin)  

Pale  yellow 

Red 

These  indicators  are  prepared  as  follows: 

Phenol  phthalein.  1.0  gram  is  dissolved  in  30.0  grams 
of  90%  alcohol.  Two  drops  of  this  solution  are  added 
to  100  c.c.  of  the  sugar  solution  to  be  tested. 

Litmus.  Powdered  litmus  is  extracted  with  boiling 
80%  alcohol  which  is  then  discarded.  The  residue  is  boiled 
with  distilled  water  and  filtered.  The  filtrate  is  divided 
into  two  equal  parts,  one  of  these  is  neutralized  with  sul- 
phuric acid  and  then  intimately  mixed  with  the  other 
portion  and  this  process  is  repeated  until  exact  neutrality 
of  the  whole  solution  has  been  attained. 

To  make  litmus  paper,  a  certain  volume  of  the  above 
solution  is  divided  into  two  equal  portions.  One  of  these 
portions  is  made  faintly  acid  with  sulphuric  acid  and  strips 
of  filter  paper  are  dipped  into  the  same  and  -then  dried. 
The  other  portion  is  made  faintly  alkaline  with  a  weak 
sodium  hydrate  solution  and  also  used  for  preparing  filter 
paper  strips  in  the  same  way. 

The  former,  the  red  litmus  paper  serves  as  an  indicator 
for  alkaline  solutions  which  turn  it  blue;  the  other,  the 
blue  litmus  paper  serves  as  an  indicator  for  acid  solutions, 
which  turn  it  red.  Care  must  be  taken  to  preserve  both 
kinds  of  filter  paper  in  well  stoppered  bottles  and  undue 
exposure  to  strong  light  must  be  avoided. 


136  SUGAR  ANALYSIS 

Rosolic  add  (Corallin).  Dissolve  3.0  grams  of  rosolic 
acid  in  150  c.c.  of  90%  alcohol  and  make  the  solution 
almost  neutral.  To  25  c.c.  of  a  sugar  solution  to  be  tested, 
add  2  drops  of  the  rosolic  acid  solution  and  10  c.c.  of  neutral 
ether.  Shake  well,  and  then  allow  the  fluids  to  separate — 
a  yellow  color  indicates  acidity,  a  red  color,  alkalinity. 

Considering  all  things,  phenol  phthalem  and  litmus 
solution  appear  to  be  the  most  satisfactory  indicators 
for  general  sugar  work;  the  color  change  exhibited  by 
phenol  phthalei'n  is  well  denned  even  in  sugar  solutions 
of  a  distinctly  yellowish  cast. 

It  must  be  borne  in  mind  however  whichever  indicator 
is  selected,  that  indicators  vary  considerably  in  their  sensi- 
tiveness of  reaction  and  therefore  any  given  set  of  compara- 
tive determinations  must  be  carried  through  with  one  and 
the  same  indicator. 

Determination  of  Alkalinity.  To  get  a  qualitative 
indication  as  to  whether  a  sugar  is  alkaline,  acid  or  neutral, 
dissolve  two  grams  of  the  sample  in  about  eight  or  ten 
cubic  centimeters  of  distilled  water.  On  this  solution 
pour  carefully  an  alcoholic  solution  of  phenol  phthalem. 

If  the  sample  is  alkaline,  a  red  ring  is  formed  at  the 
contact  zone  of  the  two  liquids. 

If  there  is  no  color-reaction,  a  few  drops  of  alcoholic 
phenol  phthalem  solution  and  one  drop  of  a  tenth-normal 
alkali  solution  are  mixed  with  100  c.c.  of  distilled  water, 
and  about  10  grams  of  the  sample  under  examination  are 
dissolved  in  this  liquid. 

If  the  latter  becomes  decolorized,  the  sample  is  acid, 
if  the  solution  retains  its  red  color,  the  sample  must  be 
pronounced  neutral. 

The  alkalinity  of  different  sugar  products  may  be  caused 
by  potassium,  by  sodium,  by  lime,  or  even  partially  by 
free  ammonia.  It  has,  however,  become  customary  to 
report  the  alkalinity  in  terms  of  calcium  oxide  (caustic 
lime). 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    137 

Alkalinity  is  determined  quantitatively  by  the  addition 
of  an  acid  of  known  strength  to  a  known  weight  or  volume 
of  the  product  examined,  until  neutrality  has  been  estab- 
lished. 

The  acid  used  may  be  either  sulphuric  or  hydrochloric 
acid,  the  first  of  these  is  the  one  most  commonly  employed. 

The  acid  used  is  generally  of  "  tenth-normal  "  strength. 
To  prepare  this  there  are  needed  of- 

Sulphuric  oxide       4.00   grams  SOs      in  1  liter  of  water. 
Hydrochloric  acid  3.637      "      HC1 
Nitric  acid  6.289      M      HNO3 

The  acid  should  be  delivered  from  a  burette  divided 
into  tenths  of  a  cubic  centimeter. 

To  effect  an  alkalinity  determination,  10  to  20  grams 
of  the  product  to  be  tested  are  weighed  and  dissolved, 
or,  if  a  solution  is  to  be  examined,  from  10  to  20  cubic 
centimeters  are  measured  out  and  placed  in  a  porcelain 
dish.  A  few  drops  of  the  indicator  having  been  added, 
the  acid  is  allowed  to  flow  in  from  a  burette  until  the  change 
in  color  of  the  indicator  shows  the  reaction  to  be  finished. 

1  cubic  centimeter  of  -^  (tenth  normal)  sulphuric  acid 

corresponds  to  0.0040  gram  sulphuric  oxide,  0.0028  gram 
calcium  oxide,  or  0.0047  gram  potassium  oxide. 

The  number  of  cubic  centimeters  of  acid  used,  multi- 
plied by  0.0028,  show  therefore  the  amount  of  calcium 
oxide  present. 

Example.  25  cubic  centimeters  of  a  sugar  solution 
(specific  gravity  1.198)  required  2.4  cubic  centimeters 

^T:  sulphuric  acid  to  effect  neutralization.  This  repre- 
sents 0.0028X2.4  =  0.00672  gram  calcium  oxide 

25.0  :  0.00672::  100  ;  x. 


138  SUGAK  ANALYSIS 

£  =  0.02688  per  cent  calcium  oxide.  This  is  percentage 
by  volume.  If  percentage  by  weight  is  required,  the  above 
value  must  be  divided  by  the  specific  gravity  of  the  solu- 
tion, or  if  a  specific-gravity  determination  and  this  sub- 
sequent calculation  are  to  be  avoided,  the  solution  to  be 
tested  must  in  the  first  place  be  weighed  out,  and  not 
measured. 

A  method  devised  by  Pellet  permits  determining  sepa- 
rately the  alkalinity  due  to  lime  and  that  due  to  the  alka- 
lies (potassium,  sodium)  liberated  by  the  action  of  lime 
from  their  organic  acid  salts. 

Total  alkalinity:  Titrate  with  sulphuric  acid  at  the 
boiling  point  using  litmus  as  indicator. 

Soda  and  potassa  alkalinity:  In  a  certain  volume  of 
the  sugar  juice  precipitate  the  lime  as  saccharate,  by  the 
addition  of  an  equal  volume  of  alcohol.  Filter,  and  in  the 
filtrate  determine  the  alkalinity  due  to  the  soda  and  potassa. 
This  value  however  is  also  generally  expressed  in  terms 
of  lime  (CaO). 

If  no  stress  is  laid  upon  knowing  whether  the  alkalinity 
is  due  to  lime  or  to  the  alkalies,  put  50  c.c.  of  the  solution 
to  be  tested  into  a  white  porcelain  dish,  use  litmus  as  indi- 
cator and  titrate  with  sulphuric  acid  solution  of  such  strength 
that  1  c.c.  is  equivalent  to  0.001  gram  of  lime  (CaO). 

Following  is  the  standard  method  of  determining  alka- 
linity in  raw  sugars,  as  published  in  1910  by  the  Directo- 
rate of  the  Verein  der  Deutschen  Zucker  Industrie,  and 
here  given  by  courtesy  of  Professor  Dr.  Alexander  Herzfeld. 

In  order  to  make  alkalinity  determinations,  the  follow- 
ing reagents  are  necessary: 

I.  The  Concentrated  Solution  of  Phenol  Phthalein.  Dis- 
solve one  part  of  phenol  phthalein  in  thirty  parts  of  90% 
alcohol.  To  carry  out  the  test  two  drops  of  this  solution 
are  taken  for  every  100  c.c.  of  the  solution  to  be  tested. 

Technical  phenol  phthalein  frequently  has  a  slightly 
acid  reaction,  but  no  attention  whatever  is  paid  to  this, 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    139 

in  other  words,  the  phenol  phthalei'n  solution  is  not  made 
either  neutral  or  faintly  alkaline  before  use. 

II.  Water  of  Solution.     For  the  preparation  of  the  water 
used  for  dissolving,  there  is  added,  to  a  large  quantity  of 
freshly   boiled   distilled   water,    1/2,000   of   its   volume   of 
phenol  phthaleiin  solution,  thus,  for  instance,  to  ten  liters 
of  water  5  c.c.  of  the  phenol  phthale'in  solution  are  added, 
and  then  this  solution  is  made  strongly  alkaline  with  a 
solution  of  caustic  soda,  until  the  fluid  retains  a  pronounced 
red  color.     As  this  red  coloration  disappears  again  after 
one  or  two  days,  the  amount  of  water  used  for  dissolving 
should  only  be  prepared  in  an  amount  sufficient  for  the 
time.     It  should,  however,  always  be  prepared  a  few  hours 
before  use. 

III.  The  Titration  Add.     This  titration  acid  is  prepared 
in  such  a  way  that  1  c.c.  of  the  same  corresponds  to  a  lime 
alkalinity   of   0.0001.     Such    a   solution   can   be   prepared 
with  a  sufficient  degree  of  accuracy  if  one  dilutes  36  c.c. 
of  1/1  normal  sulphuric  acid  with  water  up  to  a  volume  of 
ten  liters. 

IV.  Titration  Alkali.     For  this  purpose  one  uses  a  solu- 
tion of  caustic  soda  which  is  so  diluted  that,  as  with  the 
sulphuric  acid,  1  c.c.  corresponds  to  a  lime  alkalinity  of 
0.0001.     For  the  present  purpose  it  suffices  to  standardize 
such  diluted  caustic  soda  solution  against  the  titration  acid 
prepared  as  above  directed. 

Determination  of  Alkalinity.  In  order  to  test  a  raw 
sugar  for  its  alkalinity,  one  weighs  out  ten  grams  of  raw 
sugar,  and  measures  out  100  c.c.  of  the  faintly  red  water 
of  solution,  which  has  been  prepared  as  above  described, 
and  neutralizes  the  same  in  a  white  porcelain  dish  as  care- 
fully as  possible,  until  it  is  perfectly  colorless,  employing 
for  this  purpose  the  titration  acid,  the  preparation  of  which 
has  been  previously  described.  Then  one  adds  a  sufficient 
amount  of  the  titration  alkali  solution  to  it  until  the  fluid 
again  assumes  a  faintly  red  coloration. 


140  SUGAR  ANALYSIS 

This  coloration  must,  however,  be  only  sufficiently 
marked  that  it  can  be  caused  to  disappear  again,  immediately 
before  the  addition  of  the  raw  sugar,  by  the  addition  of  1  c.c. 
of  the  standard  titration  acid. 

Then,  without  delay,  the  ten  grams  of  raw  sugar  which 
have  been  previously  weighed,  are  dissolved  in  the  fluid.  If 
the  indicator-red  coloration  of  water  remains  on  dissolving 
the  sugar  in  it,  or  if  it  grows  more,  intense,  then  the  sugar  is 
alkaline;  if  the  red  coloration  disappears,  the  sugar  is  acid. 

In  case  one  is  in  doubt,  one  determines  the  true  condi- 
tion by  titrating  both  with  the  standard  acid  as  well  as 
with  the  standard  alkali,  in  order  to  decide  in  which  way 
the  color  turns. 

With  dark  sugars,  as  a  rule,  100  c.c.  of  the  water  of 
solution  are  not  sufficient,  and  then  as  much  water  must 
be  used  as  is  necessary  in  order  to  have  the  sugar  solution 
sufficiently  light  in  color  that  the  titration  may  be  carried 
out.  This,  however,  is  permissible  only  then  when  it  is 
found  impossible  to  get  on  with  100  c.c.  In  this  connection 
it  must  be  specifically  remarked  that  in  the  application 
of  this  method  neutral  sugars  are  classed  together  with 
alkaline  sugars. 

Acidity  of  Sugars.  To  determine  the  acidity  of  a 
solution,  syrup,  molasses,  etc.,  the  same  course  is  followed 
as  above  described,  only,  of  course,  the  solution  added  to 
effect  neutralization  is  one  of  sodium  hydrate  (caustic 
soda),  potassium  hydrate  (caustic  potash),  or  calcium 
hydrate  (slaked  lime),  and  the  change  of  color  of  the  indicator, 
if  litmus,  must  be  from  red  to  blue,  or  if  phenol  phthalei'n 
or  rosolic  acid  is  employed,  from  colorless  to  a  bright 
crimson.  Of  these  solutions  the  calcium  hydrate  solution 
is  least  desirable,  as  the  carbonic  acid  of  the  atmosphere 
readily  precipitates  in  it  calcium  carbonate,  and  so  changes 

the  strength  of  the  solution.     A  yj~  sodium-hydrate  solution 
contains  3.996  grams  NaOH  in  1  liter. 


CONSTITUENTS  OF  SUGAR  OTHER  THAN  SUCROSE    141 

To  carry  out  an  acidity  determination  on  a  sugar  solu- 
tion or  juice,  place  50  c.c.  of  it  in  a  white  porcelain  dish. 
Add  five  drops  of  phenol  phthalei'n  solution  as  indicator 

and  titrate  with   a  -^  solution  of    sodium  or  potassium 

hydrate.  Appearance  of  a  pink  color  indicates  the  end 
point  of  the  reaction. 

Sulphurous  Oxide  in  Sugar.  Qualitative  Test.  To  test 
qualitatively  for  sulphurous  oxide  dissolve  from  10  to  20 
grams  of  the  sugar  in  about  25  cubic  centimeters  of  distilled 
water.  Pour  into  a  flask,  and  add  about  5  grams  of  chem- 
ically pure  zinc  (free  from  sulphur),  and  5  cubic  centimeters 
of  chemically  pure  hydrochloric  acid.  Suspend  a  paper 
moistened  with  acetate  of  lead  solution  in  the  neck  of  the 
flask.  If  sulphur  dioxide  is  present,  it  will  be  liberated  from 
its  combinations  as  sulphuretted  hydrogen,  and  this  gas 
will  turn  the  acetate  of  lead  on  the  paper  a  brown  or  a  black 
color,  owing  to  the  formation  of  sulphide  of  lead. 

Sulphurous  oxide  can  also  be  qualitatively  tested  for 
by  impregnating  filter  paper  with  a  mixture  of  starch  and 
potassium  iodide.  This  paste  is  prepared  by  dissolving 
2.0  grams  of  starch  in  about  200  c.c.  of  boiling  water  and  then 
adding  0.20  gram  iodide  of  potassium  in  5  c.c.  of  water. 
Paper  thus  prepared  should  be  well  dried  and  kept  in  closed 
bottles  or  jars.  On  being  moistened  and  dipped  into  the 
solution  to  be  examined,  even  small  amounts  of  sulphurous 
acid  will  be  indicated  by  the  appearance  of  a  blue  color  on 
the  paper,  caused  by  the  iodine  which  is  liberated  and 
which  reacts  with  the  starch. 

Quantitative  Determination  of  sulphurous  oxide  can  be 
made  by  either  the  gravimetric  or  the  volumetric  method. 

a.  By  Gravimetric  Method.  500  grams  of  the  sugar 
to  be  tested  are  dissolved  in  a  flask  and  made  up  to  a 
volume  of  500  c.c.  with  distilled  water,  5  grams  of  chemically 
pure  glacial  phosphoric  acid  are  added,  the  solution  poured 
into  a  distilling  flask,  attached  to  a  condensing  worm  and 


142  SUGAR  ANALYSIS 

a  current  of  washed  carbonic  acid  gas  led  into  the  flask 
insuring  therein  an  atmosphere  of  carbonic  acid  gas.  When 
this  has  been  achieved,  a  flame  is  lighted  under  the  flask 
and  distillation  commenced. 

The  distillate  is  received  in  50  c.c.  of  chemically  pure 
bromine  water.  When  at  least  50  c.c.  have  distilled  over — 
the  current  of  carbonic  acid  gas  being  constantly  main- 
tained in  the  flask  in  the  meantime — the  receiving  flask  is 
changed,  and  the  operation  is  continued  until  another  50 
c.c.  of  distillate  have  been  secured. 

Any  sulphite  which  may  have  been  present  in  the  sample 
will  be  found  in  the  distillate,  changed  to  sulphuric  acid. 
To  this  are  now  added  10  c.c.  of  a  20%  barium  chloride 
solution  and  the  same  thoroughly  boiled.  The  white  pre- 
cipitate of  barium  sulphate  is  filtered  oat,  well  washed 
with  water  to  remove  any  adhering  barium  chloride,  dried, 
ignited,  weighed,  and  the  amount  of  sulphurous  oxide 
originally  present  in  the  sugar  calculated  by  the  equation: 

BaS04  :  862  •  •  Weight  of  the  barium  sulphate  found  :  x 
233.5:64::-  -:x 

If  it  is  desired  to  express  the  finding  in  terms  of  sulphurous 
acid,  the  calculation  to  be  made  is  as  follows: 

BaS04  -  H2SO3  : :  Weight  of  the  barium  sulphate  found  :  x 
233.5:82::-       -:x 

b.  By  Volumetric  method.*  Distil  100  grams  of  the 
solution  to  be  tested  in  a  current  of  carbon  dioxide  after 
the  addition  of  about  5  c.c.  of  a  20%  solution  of  glacial 
phosphoric  acid  until  50  c.c.  have  passed  over.  Collect 

*  Bulletin  No.  107  (Revised)  Reprint,  July  1,  1909,  Bureau  of  Chem- 
istry. 


CONSTITUENTS  OF  SUGAK  OTHEE  THAN  SUCROSE    143 

the  distillate  in  a  TT:  iodin  solution  in  a  flask  closed  with  a 

stopper  perforated  with  two  holes,  through  one  of  which 
the  end  of  the  condenser  passes  and  through  the  other 
a  U-tube  containing  a  portion  of  the  standardized  iodin 

solution.     Twenty-five   c.c.   of   y^   iodin  solution  may  be 

employed,  diluted  with  water  to  give  the  desired  volume. 
The  method  and  apparatus  may  be  simplified  without 
material  loss  in  accuracy  by  omitting  the  current  of  CO2, 
adding  10  c.c.  of  phosphoric  acid  instead  of  5  c.c.,  and 
dropping  into  the  distilling  flask  a  piece  of  NaHCOs,  weigh- 
ing not  more  than  a  gram,  immediately  before  attaching 
to  the  condenser.  The  C02  liberated  is  not  sufficient 
to  expel  the  air  entirely  from  the  apparatus,  but  will  prevent 
oxidation  to  a  large  extent.  The  U-tube  trap  may  also  be 
omitted  if  the  end  of  the  condenser  tube  is  made  to  extend 
below  the  surface  of  the  iodin  solution,  and  the  distilla- 
tion conducted  with  a  steady  flame.  When  the  distilla- 
tion is  finished  wash  the  contents  of  the  U-tube  into  the 
flask  and  determine  the  excess  of  iodin  with  standard 
thiosulphate  solution.  On  account  of  its  lack  of  perma- 
nence the  iodin  solution  employed  should  be  titrated  from 

?? 

time  to  time  with  a  TQ  thiosulphate  solution  (containing 

24.8  grams  ^28263 -SH^O  per  liter).     1   c.c.  of  yH  iodin 

solution  is  equivalent  to  0.0032  gram  of  SOo. 

H.  Pellet  has  suggested  a  simple  and  rapid  method  of 
estimating  sulphurous  acid,  free  and  combined,  in  sugar 
house  products.* 

It  is  an  adaptation  of  the  Dujardin  sulphur ooenometric 
tube  used  for  testing  wine  in  France,  and  consists  essen- 
tially of  a  tube  which,  for  use,  is  set  up  in  a  vertical  posi- 

*  Sucrerie  Beige,  1910,  Vol.  XXXIX,  p.  152.  Intern.  Sugar  Jour., 
1911,  Vol.  XIII,  p.  48.  .. 


144  SUGAR  ANALYSIS 

tion.  Into  this  are  poured  successively  prescribed  amounts 
of  the  sugar  solution  to  be  tested,  of  potash  solution,  an 
acid  and  some  starch  as  indicator.  Titration  is  carried 
out  with  standard  iodine  solution  until  the  blue  color 
appears.  From  the  graduation  which  is  etched  over  the 
upper  part  of  the  tube,  the  sulphurous  acid  content  of  the 
solution  examined  can  be  read  off  directly  in  milligrams 
per  liter. 

Iron  Oxide  in  Sugars.  Place  about  25  c.c.  of  the  sugar 
solution  to  be  examined  in  a  white-glass  test-tube.  Add 
5  drops  of  concentrated  hydrochloric  acid  and  20  drops 
of  ammonium-  or  potassium-sulpho-cyanide  solution  and 
mix  well. 

Add  about  10  c.c.  of  ether,  shake  well,  and  allow  the 
ether  to  separate.  If  iron  is  present  the  ether  will  show 
a  red  coloration. 


CHAPTER    VIII 
MATERIALS    USED    IN    THE    SUGAR    INDUSTRY 

Bone-Black.  Water.  Heat  10.0  grams  at  130°  C.- 
140°  C.  to  constant  weight,  making  the  first  weighing  after 
three  hours. 

To  execute  the  following  determinations  the  bone- 
black  must  be  ground  to  a  fine  powder. 

Carbon,  Sand  and  Clay.  To  5.0  grams  of  bone-black 
add  some  water  and  25  c.c.  concentrated  hydrochloric 
acid.  Boil  for  15  minutes,  transfer  to  a  dried  and  tared 
filter  and  wash  with  hot  water  until  disappearance  of  the 
acid  reaction.  Dry  filter  with  contents  at  110°  C.,  to  con- 
stant weight,  and  burn  in  weighed  crucible.  Weight  of 
residue  in  crucible  =  sand  and  clay;  this  weight  subtracted 
from  weight  of  carbon,  sand  and  clay  =  carbon. 

Calcium  Carbonate.  Place  from  3  to  5  grams  of  the 
bone-black  in  a  Geissler,  Schrotter  or  similar  apparatus. 
The  latter  is  weighed  with  its  charge  of  bone-black,  and 
hydrochloric  or  sulphuric  acid,  the  acid,  of  course,  being 
kept  in  its  separate  compartment  for  this  weighing.  The 
acid  is  then  admitted  to  the  bone-black,  the  latter  is  attacked 
by  the  acid  and  the  carbonic  acid  gas  generated  is  permitted 
to  escape.  Dry  air,  free  from  carbonic  acid  gas  is  then 
drawn  through  the  apparatus  and  the  latter  reweighed. 
The  loss  in  weight  represents  the  carbonic  acid  gas  liberated 
and  is  calculated  to  its  equivalent  of  calcium  carbonate 
by  the  formula: 

44  :  100 ::,  weight  of  C02  found  :  x 

145 


146  SUGAR  ANALYSIS 

x  =  calcium  carbonate,  and  this  is,  as  usual,  expressed 
in  percentage  on  the  bone-black  used. 

This  determination  is  also  frequently  effected  in  a 
Scheibler  apparatus  which  is  based  on  a  direct  volumetric 
determination  of  the  carbonic  acid  gas. 

Free  Lime.  (CaO).  Two  carbonic  acid  gas  determina- 
tions are  required. 

The  first  of  these  is  made  on  the  original  bone-black 
sample,  as  above  described;  the  second  is  carried  out 
on  a  sample  of  the  bone-black  which  has  been  moistened 
several  times  with  a  concentrated  solution  of  ammonium 
carbonate  and  which  has  then  been  heated  repeatedly 
and  sufficiently  to  cause  the  volatilization  of  that  reagent. 
Care  must  however  be  taken  not  to  heat  to  redness.  By 
such  treatment  the  free  lime  is  of  course  converted  into 
calcium  carbonate  and  from  the  difference  in  carbonic 
acid  found  in  the  two  determinations  the  amount  of  free 
lime  is  readily  calculated. 

Calcium  Sulphide.  To  25  grams  of  bone-black  add 
0.5-1.0  gram  potassium  chlorate.  Mix  intimately,  then 
moisten  with  hot  water  and  add  100  c.c.  pure  hydrochloric 
acid.  After  evolution  of  the  carbonic  acid  gas  boil  for 
15  minutes.  Filter  into  a  500  c.c.  flask,  wash  residue  on 
filter  until  tests  with  barium  chloride  solution  show  that 
all  of  the  sulphates  have  passed  into  the  flask;  cool,  fill 
up  to  the  500  c.c.  mark,  mix  well  and  take  200  c.c.  of 
filtrate  (10.0  grams  of  bone-black).  In  this  portion  pre- 
cipitate the  total  sulphates  by  barium  chloride,  filter  and 
weigh.  This  weight  of  barium  sulphate  represents  the 
calcium  present  in  the  bone-black  both  as  calcium  sulphate 
and  as  calcium  sulphide.  From  this  weight  subtract  the 
amount  of  calcium  sulphate  present  as  such,  to  be  determined 
as  directed  below,  and  multiply  the  remainder  by  0.3087. 
The  value  so  found  is  to  be  recorded  as  calcium  sulphide. 

Calcium  Sulphate.  Proceed  exactly  as  directed  above 
except  that  the  treatment  with  the  potassium  chlorate  is 


MATEEIALS  USED  IN  THE  SUGAR  INDUSTRY     147 

omitted.  The  weight  of  the  barium  sulphate  found  mul- 
tiplied by  0.5828  represents  the  calcium  sulphate  in  the 
bone-black. 

Iron  and  Aluminum  Oxides.  5.0  grams  are  dissolved 
in  25  c.c.  cone,  nitric  acid  (Sp.Gr.  1.2)  and  12.5  c.c.  hydro- 
chloric acid  (Sp.  Gr.  1.12)  and  the  solution  is  made  up  to 
a  volume  of  500  c.c.  with  water.  This  solution  is  filtered 
and  100  c.c.  of  the  nitrate  (  =  1.0  gram  of  bone-black)  are 
placed  in  a  250  c.c.  flask,  25  c.c.  sulphuric  acid  (Sp.  Gr.  1.84) 
are  added  and  the  mixture  shaken  several  times  during 
5  minutes.  Then  100  c.c.  of  a  95%  alcohol  are  added, 
the  mixture  is  cooled,  made  up  to  the  250  c.c.  mark  with 
alcohol,  well  shaken,  again  made  up  to  the  mark  with  alcohol 
as  there  is  a  decided  contraction  in  volume,  and  once  more 
well  shaken. 

After  one  half  hour's  standing,  the  solution  is  filtered. 
100  c.c.  are  evaporated  in  a  platinum  dish  until  all  the  alcohol 
is  removed,  then  poured  into  a  beaker,  about  50  c.c.  of 
water  are  added  and  heated  to  boiling.  The  solution  is 
next  made  alkaline  with  ammonium  hydrate  and  the  super- 
fluous ammonia  boiled  off.  After  cooling  the  solution  is 
filtered,  the  precipitate  is  well  washed  with  hot  water, 
dried,  ignited  and  weighed  as  Fe203+Al20s. 

Tri-calcic  Phosphate.  Take  5.0  grams  of  bone-black, 
add  50  c.c.  nitric  acid  (Sp.  Gr.  1.42)  and  50  c.c.  pure  cone, 
sulphuric  acid.  Boil  gently  for  one  half  hour.  Cool, 
wash  into  a  500  c.c.  flask,  fill  to  mark,  mix  well  and  pour 
through  a  dry  filter.  In  50  c.c.  of  the  filtrate  (  =  0.5  gm. 
bone-black)  determine  phosphoric  acid  by  the  ammonium 
molybdate  method  to  be  discussed  later. 

From  the  weight  of  the  magnesium  pyrophosphate 
found,  the  amount  of  tricalcic  phosphate 
is  obtained  by  the  formula: 

Mg2P207  :  Ca3(P04)2 ::  -  :  x 
222.6  :  310  ::  -  :  x 


148  SUGAR  ANALYSIS 

Sugar  in  Bone-black.  Take  100.0  grams  of  bone-black, 
boil  four  or  five  times,  for  10  minutes  each  time,  with  150 
c.c.  water.  To  these  washings  add  a  few  drops  of  sodium 
carbonate  solution.  Evaporate  to  small  bulk,  place  in  a 
100  c.c.  flask,  neutralize  carefully  (using  phenol  phthalei'n 
solution  as  indicator),  with  acetic  acid,  add  basic  lead  acetate, 
fill  up  to  mark,  and  polarize  in  a  200  m.m.  tube.  The 
polarization  found  X  0.26  =  percentage  of  sucrose  in  the 
moist  bone-black.  Determine  the  percentage  of  moisture 
separately  and  calculate  result  to  dry  substance. 

Example.  Water  in  bone-black  examined  =  25.0%,  then 
dry  substance  =  75.0%.  Sucrose  found  in  moist  bone-black 
=  0.70%.  Then: 

75.0  :  0.70::  100  :x 
z  =  0.93%  sucrose  in  dry  bone-black. 

Organic  Matter  in  Bone-black.  Boil  100  grams  of  sample 
with  100  c.c.  caustic  soda  solution,  of  10°  Brix  density, 
for  three  minutes.  The  solution  is  poured  into  a  test- 
tube  and  color  examined.  If  colorless  or  of  a  very  pale 
yellow,  the  revivification  is  satisfactory;  if  dark  yellow 
or  brown  the  bone-black  has  been  underburned;  if  green 
in  tint,  overburned. 

Decolorizing  Power  of  Bone-Black .  For  this  determina- 
tion use  some  colorimeter,  for  instance  Stammer's  or 
Lovibond's  tintometer. 

Dry  the  bone-black,  which  is  to  be  tested,  at  140°  C. 
Make  up  a  solution  of  raw  sugar  or  molasses  by  dissolving 
about  250  grams  in  water  and  make  the  volume  of  the 
solution  up  to  1000  c.c. 

In  a  large  porcelain  dish  place  100  grams  of  the  bone- 
black  and  pour  over  it  400  c.c.  of  the  sugar  or  molasses 
solution.  Weigh  dish  and  contents.  Heat  and  keep 
boiling  for  five  minutes.  Cool,  reweigh  and  replace  the 
water  lost  in  the  boiling.  Mix  well,  filter  through  a  dry 


MATERIALS  USED  IN  THE  SUGAR  INDUSTRY     149 

filter  and  then  determine  the  color  of  the  unfiltered  and  of 
the  filtered  solution. 

Example.     Color  of  unfiltered  solution.  =  30 . 0 

Color  of  filtered  solution  =  5.0 


Decolorization  effected  by  the  bone- 
black  =  25.0 

Expressed  in  percentage  of  the  original  color  this  is: 

30.0  :25::100:z 
z  =  83.8%  decolorization  effected. 

Weight  of  B one-Black.  The  impurities  not  removed  by 
washing  and  revivification  gradually  accumulate  in  the 
black  and  cause  an  increase  in  its  weight. 

New  bone-black  ranges  in  weight  from  about  42  to  49 
Ibs.  per  cubic  foot,  depending  to  a  considerable  degree 
on  the  size  of  its  grain.  It  is  best  to  use  a  box  of  one  cubic 
foot  capacity  for  these  weight  determinations,  taking  care 
to  have  the  same  filled  in  the  same  manner  and  to  the  same 
extent  every  time.  The  weight  can  also  be  determined  in 
smaller  vessels,  flasks,  etc.,  but  the  results  are  not  as  reliable. 
Phosphoric  Acid  Paste.  From  the  fine  bone-black 
dust  which  accumulates  in  process,  an  excellent  defecating 
material  can  be  prepared  by  the  use  of  sulphuric  or  hydro- 
chloric acid. 

The  materials  are  intimately  mixed  in  vats  by  means  of 
mechanical  stirrers  and  according  to  the  proportions  of  bone- 
black  dust  and  of  acid  chosen,  either  free  phosphoric  acid 
(H3PO4)  or  monocalcic  phosphate  CaH^PO^  is  pro- 
duced. This  paste  should  contain  from  12-14%  of  P2Os. 

The  total  P2O5  and  the  soluble  P205  are  determined  in 
the  iollowing  manner. 

Reagents  Used.  Molybdic  Solution:  Dissolve  100  grams 
molybdic  acid  in  400 'grams,  or  417  c.c.  ammonic  hydrate 


150  SUGAR  ANALYSIS 

(sp.gr.  =0.96),  and  pour  the  solution  thus  obtained  into 
1500  grams,  or  1250  c.c.  nitric  acid  (sp.gr.  =  1.20).  Keep 
the  mixture  in  a  warm  place  for  several  days,  or  until  a 
portion  heated  to  40°  C.  deposits  no  yellow  precipitate  of 
ammonium-phospho-molybdate.  Decant  the  solution  from 
any  sediment,  filter  and  preserve  in  a  glass-stoppered  vessel. 

Magnesia  mixture:  Weigh  out  110  grams  of  crystal- 
lized magnesium  chloride  (MgCl2+6H2O),  also,  280  grams 
ammonium  chloride.  Dissolve  this  ammonium  chloride 
in  distilled  water,  and  add  700  c.c.  of  ammonic  hydrate 
(sp.gr.  0.96).  Into  this  solution  pour  the  magnesium 
chloride,  previously  dissolved  in  some  distilled  water, 
and  make  the  total  volume  of  the  solution  up  to  2  liters. 

Ammonic  hydrate:  (For  washing).  To  1  volume  of 
ammonic  hydrate  (sp.gr.  0.96)  add  3  volumes  of  distilled 
water.  Ammonic  nitrate  solution:  (For  washing).  Dis- 
solve 200  grams  ammonium  nitrate  in  distilled  water,  and 
make  the  volume  up  to  2  liters. 

Remarks:  Nitric  acid.  To  make  nitric  acid  of  sp.gr. 
1.20  from  nitric  acid  of  sp.gr.  1.42  add  1  liter  of  distilled 
water  to  each  liter  of  nitric  acid  of  sp.gr.  1.42. 

Ammonic  hydrate.  To  make  ammonic  hydrate  of 
sp.gr.  0.96  from  ammonic  Iwdrate  of  sp.gr.  0.90,  add  1620 
c.c.  of  distilled  water  to  each  liter  of  ammonic  hydrate  of 
sp.gr.  0.90. 

Analysis:  Water  Soluble  P2#5-  Weigh  out  by  differ- 
ence 2.0  grams  of  paste.  Wash  into  a  beaker  with  dis- 
tilled water  (Tr  =  60°  C.).  Stir  well  so  as  to  Leave  no  lumps. 
Then  wash  ontoa9c.m.  S.  &  S.  No.  589  filter  and  continue 
to  wash  with  warm  water  (jT  =  60°  C.)  allowing  all  of  the 
water  to  pass  through  each  time  before  adding  more,  until 
the  nitrate  measures  250  c.c.  Mix  the  washings  and  of 
these  take  62.5  c.c.  =  0.5  gram  and  proceed  as  directed 
further  on. 

Total  P205-  Weigh  out  2.0  grams  of  paste.  Wash 
into  a  beaker  with  as  little  water  as  possible,  stir  well  so 


MATEEIALS  USED  IN  THE  SUGAR  INDUSTRY     151 

as  to  leave  no  lamps.  Add  30  c.c.  concentrated  nitric  acid 
and  5  c.c.  concentrated  hydrochloric  acid.  Boil  until 
all  phosphates  are  dissolved  and  organic  matter  destroyed. 
Cool  and  dilute  to  250  c.c.  Mix  well  and  pass  through  a 
dry  filter.  Of  nitrate  take  62.5  c.c.  =0.5  gram.  Neutralize 
with  ammonic  hydrate  and  clear  with  a  few  drops  of  nitric 
acid  and  add  about  10  grams  of  ammonium  nitrate. 

Having  thus  prepared  both  solutions  proceed  in  each 
case  as  follows : 

To  the  hot  solution  (about  65°  C.)  add  200  c.c.  of  warm 
molybdic  solution  (about  35°  C.)  Bring  the  tempera- 
ture up  to  about  65°  C.  and  digest  for  about  2  hours. 
Filter,  and  wash  with  ammonium  nitrate  solution  (1:10). 
To  filtrate  add  50  c.c.  more  of  molybdic  solution,  warm 
to  65°  C.  and  set  aside  at  a  temperature  of  about  50°  C. 
for  12  hours  more  to  test  whether  all  has  been  precipitated. 
Dissolve  precipitate  on  filter  with  hob  water  and  ammonic 
hydrate  (sp.gr.  0.90)  and  wash  into  a  beaker  to  a  bulk  not 
to  exceed  100  c.c.  Nearly  neutralize  with  hydrochloric 
acid,  cool,  add  125  c.c.  of  magnesia  mixture  from  a  burette 
under  constant  stirring,  one  drop  per  second.  After  15 
minutes  add  30  c.c.  ammonic  hydrate  (sp.gr.  0.96).  Allow 
to  stand  for  12-15  hours,  filter,  wash  with  dilute  ammonic 
hydrate,  dry,  ignite  intensely  for  10  minutes  and  weigh 
the  magnesium  pyro-phosphate  (Mg2P207). 

Retest  the  filtrate  by  adding  25  c.c.  more  of  magnesia 
mixture  and  allow  to  stand  for  6  hours  more  to  see  whether 
any  further  precipitation  occurs.  If  a  further  precipitate 
is  formed,  filter  it  out,  treat  as  before  directed  and  add 
its  weight  to  that  of  the  precipitate  previously  obtained. 

Calculate  result  as  follows: 

Mg2P2O7  :  P205::-    -  :  x 
222.6         :  142    ::-    -  :  x. 
or  multiply  by  factor*  0.6379. 


152  SUGAR  ANALYSIS 

Limestone  furnishes  the  caustic  lime  and  the  carbonic 
acid  gas  both  of  which  are  extensively  used  in  certain  proc- 
esses of  sugar  refining.  In  selecting  a  limestone  for  sugar 
purposes  care  must  be  had  to  secure  a  quality  which  is  free 
from  any  considerable  amounts  of  silica,  gypsum,  clay, 
magnesium  salts  and  alkalies. 

When  limestone  is  subjected  to  a  heat  of  between  700° 
and  1200°  C.  it  is  decomposed  into  calcium  oxide  and 
carbonic  acid  gas,  the  latter  in  fact  begins  to  be  set  free 
even  at  a  temperature  but  little  above  400°  C. 

A  very  convenient  method  for  determining  both  the 
calcium  oxide  and  the  carbonic  acid  gas  is  given  by  G. 
Lunge,*  as  follows: 

Calcium  oxide  (CaO).  100  grams  of  the  caustic  lime 
are  carefully  slaked  and  run  into  a  500  c.c.  flask.  The 
volume  is  made  up  to  500  c.c.  and,  while  agitating  the  mix- 
ture constantly,  100  c.c.  are  removed  by  a  pipette.  These 
100  c.c.  are  run  into  another  500  c.c.  flask,  made  up  to 
volume,  well  mixed  and  from  this  solution  25  c.c.  (  =  1  gram 
caustic  lime)  are  taken  for  analysis. 

To  this  solution  a  small  amount  of  an  alcoholic  solution 
of  phenol  phthalein  is  added  and  then  the  solution  is  titra- 
ted with  normal  hydrochloric  acid  until  the  rose  color 
has  disappeared.  This  occurs  when  all  free,  uncombined 
calcium  oxide  is  satisfied,  but  ere  the  calcium  carbonate 
is  attacked.  Each  c.c.  of  the  normal  hydrochloric  acid  = 
0.028  gram  CaO.  This  operation  must  be  executed  care- 
fully and  under  constant  shaking,  in  order  to  have  it  yield 
reliable  results. 

Carbonic  Acid  Gas  (CO?).  The  calcium  oxide  and  the 
calcium  carbonate  are  determined  together  by  dissolving 
the  sample  in  normal  hydrochloric  acid  and  then  titrating 
back  with  normal  caustic  soda  solution.  From  the  value 
so  found  there  is  subtracted  the  amount  of  calcium  oxide 

*  Chemisch-technische  Untersuchungsmethoden,  1899,  4th  Edition, 
Vol.  I,  p.  427. 


MATERIALS  USED  IN  THE  SUGAR  INDUSTRY     153 

determined    as    above    described;     the    balance   remaining 
represents  the  calcium  carbonate. 

Of  course  the  calcium  carbonate  can  also  be  found 
by  determining  the  carbonic  acid  gas  as  described  under 
Bone-black  and  calculating  the  calcium  carbonate  corre- 
sponding to  the  amount  of  carbonic  acid  gas  so  found.* 

Coal.  Properties.  Coal  is  a  hydrocarbon,  the  essential 
components  of  which  are  volatile  combustible  matter, 
carbon,  hydrogen,  ash  and  moisture. 

The  amount  of  heat  required  to  do  a  certain  amount 
of  work  is  in  fuels  generally  expressed  in  thermal  units  and 
the  unit  commonly  used  is  known  as  the  British  Thermal 
Unit  which  represents  the  amount  of  heat  required  to 
raise  1  Ib.  of  water  from  39°  to  40°  F.,  i.e.,  1°  Fahrenheit 
in  temperature.  2545  B.T.U.  per  hour  equal  1  horse- 
power. 

The  heat  yielded  by  the  perfect  combustion  of  1  Ib.  of 
carbon  to  carbon  dioxide  is  14,500  B.T.U. ;  the  heat  yielded 
by  the  combustion  of  1  Ib.  of  carbon  to  carbon  monoxide 
(incomplete  combustion)  is  4400  B.T.U.;  the  heat  yielded 
by  the  perfect  combustion  of  hydrogen  to  water  is  62,100 
B.T.U. 

The  evaporative  value  of  a  fuel  is  the  amount  of  water 
which  1  Ib.  of  the  fuel  will  evaporate  at  normal  boiling 
point;  its  calorific  power  divided  by  the  latent  heat  of 
steam  formation,  viz.:  967.  On  an  average  1  Ib.  of  coal 
will  evaporate  8  Ibs.  of  water. 

When  coal  is  burned  under  a  boiler  the  volatile  gases 
are  at  once  set  free  and  these,  combining  with  the  necessary 
air  are  changed  to  carbon  dioxide,  either  at  once,  or,  pos- 
sibly, they  are  first  transformed  into  carbon  monoxide  and 
this,  in  turn,  is  changed  into  carbon  dioxide  by  combining 

*Also  see  HEYER,  Chem.  Ztg,  Vol.  XXXIV,  p.  102.  1909,  for  a 
general  method  of  determining,  by  means  of  a  dilute  solution  of 
ammonium  chloride,  calcium  as  oxide,  hydrate,  and  saccharate  in 
the  presence  of  calcium-carbonate,  sulphate,  etc. 


154  SUGAR  ANALYSIS 

with  more  oxygen  of  the  air.  Up  to  700°  C.  (1292°  F.) 
chiefly  carbon  dioxide  is  produced,  above  700°  C.  in  the 
presence  of  carbon,  carbon  monoxide  results. 

It  must  therefore  be  remembered  that  heated  carbon 
dioxide  is,  by  contact  with  heated  carbon,  again  reduced 
to  carbon  monoxide  which  reaction  involves  the  absorption, 
i.e.,  the  loss  of  heat  amounting  to  about  6700  B.T.U.,  and  it 
is  therefore  a  matter  of  great  importance  to  have  the  com- 
bustion properly  regulated  and  controlled,  if  the  maximum 
efficiency  is  to  be  obtained  from  a  fuel.  If  too  little  air 
is  furnished  the  fuel  for  complete  combustion,  the  carbon 
dioxide  will  react  with  more  carbon  and  become  reduced 
to  carbon  monoxide,  as  before  stated;  if  too  much  air  is 
admitted  the  furnace  and  gases  are  cooled — preheating 
the  air  for  combustion  means  a  higher  temperature  in  the 
zone  of  combustion  and  makes  for  economy. 

As  air  contains  21%  of  oxygen,  an  ideal  combustion 
of  pure  carbon  would  produce  21%  of  carbon  dioxide. 
The  use  of  anthracite  or  coke  actually  does  yield  up  to 
19%  of  carbon  dioxide,  bituminous  coal,  at  best,  yields  only 
about  16%  of  carbon  dioxide. 

Analysis.  Great  care  must  be  taken  to  secure  a  correct 
average  sample  of  the  coal  to  be  tested;  this  is  finely  ground 
and  about  25  grams  are  reserved  for  the  analysis. 

Two  samples  of  two  grams  each  are  taken.  Sample 
No.  1.  Dry  in  air-bath  at  115°  C.  to  constant  weight. 
Loss  in  weight  is  water;  the  weight  of  the  balance  remaining 
represents  the  dry  substance  in  the  coal. 

Expose  this  in  a  closed  platinum  crucible  for  three 
minutes  to  a  strong  Bunsen  flame  and  then,  without  allow- 
ing it  to  cool,  subject  it  for  three  minutes  more  to  the  in- 
tense heat  of  a  blast  lamp.  The  loss  in  weight  thus  found 
is  recorded  as  volatile  and  combustible  matter. 

Sample  No.  2.  Ignite  in  a  platinum  crucible  until  all 
of  the  carbon  is  consumed  and  only  the  ash  remains;  deter- 
mine the  weight  of  this  direct,  by  weighing. 


MATERIALS  USED  IN  THE  SUGAR  INDUSTRY     155 

State  the  percentage  of  water  in  the  sample,  but  express 
the  percentage  of  volatile  and  combustible  matter,  of 
fixed  carbon  and  of  ash,  in  terms  of  dry  substance. 

From  the  data  of  this  analysis  the  calorific  power  of 
the  coal  can  be  approximately  calculated  by  Lenoble's 
formula  in  which  : 

a  =  %  water, 

6  =  %  ash  (in  coal  as  is,  i.e.,  not  in  the  dry  substance), 
k  =  a-\-b, 

P  =  calorific  power  of  coal  in  calories.     To  change  this 
value  into  B.T.U.  multiply  by  9/5.     P  =  87.  4  (100  -/c) 

Example. 
Let  a  =  5.45 
6  =  17.90 

£  =  5.45+17.90  =  23.35 

P  =  87.4(100-23.35) 

P  =  6699  calories 


BT.U. 
o 

Carbon  in  Ash.  To  determine  how  thoroughly  a  coal 
has  been  burned,  analyze  the  coal  and  the  ash  resulting 
from  its  burning  exactly  in  the  manner  described,  and  then 
calculate  the  percentage  of  carbon  lost  (i.e.,  not  burned) 
in  the  ash,  by  the  following  formula: 

Percentage  of  lost  carbon 

_%  ash  in  coal  (carbon  -f-  vol.  matter  of  ash)  100 
100  (carbon  of  coal  +  vol.  matter) 

Example. 

Coal.  Ash. 

Carbon  76.63  9.61 

Vol.  matter  10.71  1.23 

Ash  12.66  89.16 

12.66(9.61  +  1.23)100      13723.44         ,„ 
(76.63+10.71)100   ^-"=L57%  Carbon  lost  m  ash 


156  SUGAR  ANALYSIS 

Flue-Gases.  The  constituents  to  be  determined  are 
carbonic  acid,  carbon  monoxide,  oxygen  and  nitrogen 
gases. 

The  apparatus  generally  used  is  that  of  Orsat,  which 
consists  of  a  burette,  water-jacketed,  and  three  absorption 
tubes.  In  these  tubes  are  placed  respectively  the  following 
solutions : 

1.  A  solution  of  potassium  hydrate,   density  approxi- 
mately 60°  Brix; 

2.  A  solution  of  pyrogallic  acid,  10  parts  in  100  parts 
of  hot  water  and  200  parts  of  potassium  hydrate  solution, 
about  50°  Brix; 

3.  A   solution   of   cuprous   chloride.     This   is  made   as 
follows:   35  grams  of  cupric  chloride  are  dissolved  in  a  little 
water  and  stannous  chloride  is  added  in  sufficient  amount 
to  change  the  color.     The  white  precipitate  is  repeatedly 
washed    by    decantation    with    water,    guarding    the    pre- 
cipitate against  exposure  to  the  air.     Transfer  into  a  flask 
with  200  c.c.  of  concentrated  hydrochloric  acid  and  add 
about    120   c.c.   of  water.      Place  some   copper  wire  into 
the  flask  and  keep  same  carefully  closed  till  used. 

The  sample  of  flue-gas  having  been  drawn  into  the 
receiving  bottle  by  displacement  of  water,  pass  the  gas 
successively  into  the  solutions  contained  in  the  tubes.  It 
first  passes  into  the  potassium  hydrate  solution;  this  ab- 
sorbs the  carbonic  acid  gas  and  the  volume  of  which  is 
read  off  on  the  scale  of  the  burette.  The  oxygen  is  absorbed 
by  the  pyrogallic  acid  solution  and  its  volume  is  ascertained 
as  before;  the  carbon  monoxide  is  absorbed  by  the  cuprous 
chloride  solution  and  its  volume  is  measured.  The  final, 
residual  gas  is  essentially  nitrogen,  and  its  amount  is 
found  by  noting  the  difference  between  100  and  the  third 
burette  reading. 

Sulphurous  acid  gas  is  tested  for  by  shaking  up  a  sample 
of  the  gas  with  a  starch  solution  containing  iodine;  sul- 
phuretted hydrogen  is  evolved  and  detected  by  its  action 


MATERIALS  USED  IN  THE  SUGAR  INDUSTRY     157 

on  a  test-paper  moistened  with  lead  acetate  or  basic  lead 
acetate,  sulphuretted  hydrogen  turning  the  same  black. 

Sulphur.  Must  be  tested  for  its  purity;  the  sample  is 
finely  powdered,  and  one-half  a  gram  is  placed  in  a  glass- 
stoppered  flask  and  well  shaken  with  an  excess  of  saturated 
bromine  water,  about  400  c.c.  will  answer.  The  bromine 
oxidizes  the  sulphur  to  sulphuric  acid,  the  solution  is  boiled, 
expelling  the  excess  of  bromine  (use  a  hood  for  this  work), 
the  residue  is  passed  on  a  filter,  washed  well  with  hot  water, 
dried  and  weighed,  and  the  percentage  of  impurities  thus 
determined. 

Lubricating  Oils.  Alkalinity  and  Acidity  are  tested 
for  by  thoroughly  shaking  a  sample  of  the  oil  with  hot 
distilled  water  in  a  separatory  funnel,  allowing  the  water 
to  separate  and  then  testing  the  same  with  litmus  or  some 
other  standard  indicator. 

Viscosity.  This  determination  is  of  importance  in 
judging  of  the  quality  of  an  oil.  The  test  is  conducted  by 
allowing  a  measured  volume  of  water  at  some  standard 
temperature,  say  20°  C.,  to  flow  through  an  orifice  or  exit- 
tube  and  noting  the  time — in  seconds — it  requires  to  do  so. 
An  identical  volume  of  the  oil,  at  the  same  temperature, 
is  then  made  to  flow  through  the  same  opening  and  the 
time  of  its  flow  noted. 

The  specific  viscosity  of  the  oil  is  found  by  dividing 
the  time  of  its  flow  by  the  time  of  flow  of  the  water. 

Congelation.  Place  20  c.c.  of  the  oil  in  a  test-tube 
provided  with  a  thermometer  and  insert  in  a  freezing  mix- 
ture. Stir  well  and  note  the  temperature  at  which  the  oil 
stops  flowing. 

Saponification.  This  test  is  made  to  learn  whether  a 
mineral  oil  has  been  mixed  with  an  animal  or  vegetable 
oil. 

A  solution  of  potassium  hydrate  is  prepared  by  dissolv- 
ing 100  grams  of  this  reagent  in  60  c.c.  of  distilled  water. 
4  c.c.  of  this  solution  are  mingled  with  4.0  grams  of  the  oil 


158  SUGAR  ANALYSIS 

and  the  mixture  is  heated  for  an  hour.  After  cooling, 
place  in  a  separatory  funnel,  extract  the  mineral  oil  with 
ether,  and,  after  evaporation  of  the  ether,  weigh  the  mineral 
oil  which  constitutes  the  residue.  Any  discrepancy  between 
the  weight  originally  taken  —  4.0  grams  —  and  the  weight 
of  the  residue  obtained,  is  due  to  animal  or  vegetable  oils 
admixed. 

Hydrochloric  Acid.  Density.  The  density  is  deter- 
mined by  a  specific  gravity  determination  or  by  means  of 
an  hydrometer. 


24.5  Baum6  =  Sp.Gr.,  1.200  =  40.777%HC1  at  15°  C. 
20.0        "     =      ll       1.157  =  31.805         "         " 
16.0        "     =      "       1.122  =  24.874        "         " 

The  chlorine  may  also  be  determined  by  volumetric 
analysis,  using  a  nitrate  of  silver  solution  of  known  strength, 
and  potassium  chromate  as  indicator. 

Iron.  The  presence  of  iron  is  tested  for  by  ammonium 
or  potassium  sulpho-cyanide,  in  a  diluted  sample  of  the 
acid,  as  previously  described. 

Arsenic.  Mix  10  c.c.  of  the  acid  with  10  c.c.  of  water 
in  a  test-tube.  Upon  this  solution  pour  5  c.c.  freshly  pre- 
pared sulphuretted  hydrogen  water.  A  yellow  ring  developed 
at  the  zone  of  contact  after  an  hour's  standing  indicates 
arsenic.  A  quantitative  determination  of  arsenic  is  best 
made  by  the  well  known  Marsh  test. 

Water.  The  quality  of  the  water  supply  is  of  the 
greatest  importance  for  sugar  houses.  It  is  necessary  to 
determine  in  such  a  water  certain  constituents,  and  to  con- 
trol its  composition  from  time  to  time.* 

Total  Solids.  Evaporate  1  liter  of  the  water  in  a  por- 
celain or  platinum  dish  on  a  water-bath  and  dry  to  constant 
weight  at  130°  C. 

Organic  and  Volatile  Matter.  Evaporate  250  c.c.  of  the 
water  to  dryness  in  a  weighed  platinum  dish.  Dry  at  130°  C. 

*  Cairns-Waller:  Manual  of  Quantitative  Chemical  Analysis. 


MATERIALS  USED  IN  THE  SUGAR  INDUSTRY     159 

cool  and  weigh.  Heat  the  dish  at  a  low  red  heat  until  all 
organic  matter  is  destroyed.  Add  25  c.c.  of  water  saturated 
with  carbonic  acid  gas,  evaporate  to  dryness  on  a  water- 
bath,  repeat  treatment,  and  finally  dry  at  130°  C.;  cool 
and  weigh. 

The  organic  and  volatile  matter  is  represented  by  the 
difference  between  the  two  weighings. 

Silica,  Lime,  Magnesia,  Oxides  of  Iron  and  Aluminum. 
Evaporate  5  liters  of  water  nearly  to  dryness  on  a  sand- 
bath;  acidulate  with  hydrochloric  acid  and  carry  to  dryness 
on  a  water-bath.  Then  dry  at  110°  C.,  until  there  is  no 
more  odor  of  hydrochloric  acid. 

Then  take  up  with  20  c.c.  of  water  and  1  c.c.  of  con- 
centrated hydrochloric  acid,  heat  to  boiling,  add  50  c.c. 
more  water,  filter  and  wash  with  hot  water  until  a  test 
with  silver  nitrate  solution  no  longer  gives  any  turbidity. 
Dry  filter  and  contents  at  110°  C.,  ignite  in  a  weighed 
platinum  crucible,  cool  and  weigh.  This  weight  represents 
the  silica. 

Make  the  filtrate  and  washings  obtained  above,  alkaline 
with  ammonic  hydrate,  boil  out  excess  of  ammonia,  allow 
the  precipitate  to  settle,  decant  on  a  filter,  dissolve  the 
precipitate  in  a  little  hydrochloric  acid,  reprecipitate  by 
ammonic  hydrate  and  again  boil.  Filter,  wash  and  dry 
the  precipitate.  The  weight  found  is  recorded  as  the 
oxides  of  iron  and  aluminum. 

Concentrate  the  filtrate  and  washings  to  100  c.c.  Add 
1  c.c.  ammonic  hydrate,  acidify  with  hydrochloric  acid, 
boil  for  a  minute  and  again  make  alkaline  with  ammonic 
hydrate.  The  ammonium  chloride  thus  produced  pre- 
vents the  precipitation  of  magnesium  hydrate.  Add  40 
c.c.  of  ammonium  oxalate  solution  (1  part  of  oxalate  to 
24  parts  of  water).  Heat  just  to  boiling  and  allow  the 
precipitate  to  settle  for  some  hours.  Then  decant  through 
a  filter,  wash  by  decantation  with  about  25  c.c.  of  hot  water 
and  set  filtrate  aside  a;s  filtrate  A. 


160  SUGAR  ANALYSIS 

Dissolve  the  precipitate  in  the  beaker,  this  is  calcium 
oxalate  plus  a  little  magnesium  oxalate,  with  a  very  small 
amount  of  hot  dilute  hydrochloric  acid.  Make  alkaline 
with  ammonic  hydrate,  add  5  c.c.  ammonium  oxalate 
solution,  stir  well  and  then  allow  the  precipitate  to  settle. 
Filter,  wash  thoroughly  with  hot  water.  Dry  at  about 
100°  C.  and  brush  the  precipitate  into  a  clock-glass.  Burn 
the  filter  in  a  weighed  platinum  crucible  until  the  ash  is 
white.  When  the  crucible  is  cool,  add  the  precipitate  from 
the  clock-glass  to  the  crucible  contents,  moisten  the  pre- 
cipitate with  concentrated  sulphuric  acid,  place  cover  on 
crucible  and  heat  very  cautiously  to  expel  the  excess  of  the 
sulphuric  acid.  Then  ignite  strongly  for  a  few  minutes, 
cool  in  a  desiccator  and  weigh.  This  precipitate  is  calcium 
sulphate  and  this  is  calculated  to  lime  (CaO)  by  the  equa- 
tion: 

CaSO4  :  CaO::  -  :  x 

136:56    ::-':x 

Enter  the  weight  of  the  lime. 

Filtrate  A,  previously  set  aside,  contains  the  major 
portion  of  the  magnesia,  the  second  filtrate  contains  the 
balance.  Acidify  the  latter  and  washings  with  hydro- 
chloric acid,  concentrate  to  a  small  volume  and  add  it  to 
the  first.  Make  combined  filtrates  alkaline  with  ammonic 
hydrate.  Add  30  c.c.  of  a  solution  of  hydrodisodic  phos- 
phate (1  part  in  10  parts  of  water),  stir  well  with  a  glass 
rod,  avoid  however  touching  the  sides  of  the  vessel  with 
the  glass  rod.  Allow  to  stand  cold  for  12-16  hours  and 
then  test  a  few  drops  of  the  clear  fluid  with  a  few  drops 
more  of  hydro-disodic  phosphate  to  see  if  enough  of  this 
reagent  has  been  added.  If  not,  add  more,  allow  to  pre- 
cipitate as  before,  and  then  filter  on  a  small  filter.  Wash 
with  dilute  ammonic  hydrate  (1  part  of  strong  ammonic 
hydrate  and  2  parts  of  water)  until  a  few  drops  of  the  wash- 
ings show  no  more  turbidity  with  a  solution  of  barium 


MATERIALS  USED  IN  THE  SUGAR  INDUSTRY     161 

chloride  acidulated  with  hydrochloric  acid.  Dry  the 
precipitate  on  the  filter,  brush  into  a  clock-glass  and  burn 
the  filter  in  a  weighed  platinum  crucible.  Then  add  the 
precipitate  from  the  clock-glass,  ignite  again  at  bright  red 
heat,  keeping  the  crucible  covered  in  the  meantime.  Then 
remove  the  cover  and  heat  to  bright  redness  until  the  pre- 
cipitate appears  white.  A  few  drops  of  nitric  acid  added 
will  hasten  the  perfect  incineration.  Cool  in  a  desiccator 
and  weigh.  The  weight  of  the  precipitate,  which  is  mag- 
nesium pyro-phosphate,  Mg2P20r  is  calculated  to  magnesia, 
MgO,  by  the  equation: 

Mg2P207  :  2MgO::  -  :  x 
222  :  80::-  :  x. 

Enter  the  weight  of  the  magnesia. 

Sulphuric  Acid.  To  4  liters  of  the  water  add  hydro- 
chloric acid  until  acidified,  evaporate  to  about  100  c.c. 
filter  and  to  filtrate  add  20  c.c.  of  barium  chloride  solution 
(1  part  in  10  parts  of  water).  Boil  thoroughly,  test  to 
see  if  sufficient  barium  chloride  has  been  added,  boil  again, 
allow  the  precipitate  to  settle,  wash  by  decantation  with 
hot  acidulated  water  several  times,  finally  filter,  wash  with 
hot  water  until  the  test  with  nitrate  of  silver  solution  no 
longer  reacts  for  chlorine.  Dry  the  precipitate  at  about 
100°  C.  brush  the  precipitate  into  a  clock-glass,  burn  the 
filter  in  a  weighed  platinum  crucible  (moistened  with  a 
few  drops  of  sulphuric  acid),  then  add  the  precipitate  to 
the  crucible,  ignite  strongly,  cool  in  a  desiccator  and  weigh. 
The  precipitate  is  barium  sulphate  which  is  calculated  to 
sulphur  trioxide  (SOs)  by  the  equation: 

BaS04:S03::-  :x 
232.8  :  80  ::  -  :x 

Enter  as  sulphur  trioxide. 


162  SUGAR  ANALYSIS 

Chlorine.  Evaporate  4  liters  of  the  water  to  about 
100  c.c.  Determine  the  chlorine  volumetrically  by  means 
of  a  standardized  solution  of  nitrate  of  silver,  using  potas- 
sium chromate  solution  as  an  indicator.  Run  the  silver- 
nitrate  solution  in  from  a  burette  until  the  red  chromate 
of  silver  is  formed.  Enter  as  chlorine. 

Hardness.  This  term  means  the  soap-destroying  power 
of  the  water.  One  degree  of  hardness  represents  the  effect 
produced  on  a  soap  solution  by  water  which  contains  1 
grain  of  calcium  carbonate  per  gallon. 

Soap  solution:  Dissolve  10  grams  of  soda  soap  in  1 
liter  of  90%  alcohol.  Filter  and  keep  in  glass  stoppered 
bottle.  For  use  take  of  this  soap  solution  100  c.c.  add  to 
it  100  c.c.  water  and  33  c.c.  of  alcohol,  adding  the  latter 
before  the  water,  and  shaking  gently. 

Calcium  chloride  solution:  dissolve  1  gram  of  calcium 
carbonate  in  dilute  hydrochloric  acid.  Evaporate  to 
dryness,  expel  all  free  acid  and  dissolve  the  residue  in  1 
liter  distilled  water.  1  c.c.  of  this  solution  equals  1  mgr. 
of  calcium  carbonate.  Dilute  10  c.c.  of  this  solution  with 
distilled  water  to  100  c.c.  place  in  a  narrow  glass-stoppered 
bottle  and  introduce  the  soap  solution  from  a  burette,  a 
little  at  a  time,  shaking  after  each  addition  of  soap.  Pro- 
ceed thus  until  a  permanent  lather  is  formed  which  remains 
unbroken  for  5  minutes.  From  the  number  of  c.c.  of 
soap  solution  needed  for  the  formation  of  a  permanent 
lather,  the  milligrams  that  1  c.c.  of  the  soap  solution  is 
equivalent  to  is  readily  determined. 

To  determine  the  hardness  of  the  water  place  100  c.c. 
of  the  water  in  a  bottle  as  before  directed  and  proceed  ex- 
actly as  described  above.  The  number  of  c.c.  of  soap  solu- 
tion required  multiplied  by  10  =  the  number  of  mgrs.  of 
calcium  carbonate  per  liter  that  the  hardness  of  the  water 
is  equivalent  to.  This  value  multiplied  by  58,318  and 
divided  by  1,000,000  =  degrees  of  hardness  of  the  water. 
Enter  degrees  of  hardness. 


MATERIALS  USED  IN  THE  SUGAR  INDUSTRY     163 

Improvement  of  Waters.  Waters  must  frequently  be 
treated  before  they  can  be  used  in  sugar  houses. 

Organic  impurities  are  diminished  by  coagulation  with 
alum  followed  by  settling  and  filtration  through  sand  or 
diatomaceous  earth. 

An  excess  of  sulphate  of  lime  is  remedied  by  the  addi- 
tion of  sodium  carbonate.  For  improvement  of  waters 
rich  in  the  bicarbonates,  sulphates  and  chlorides  of  lime  and 
magnesia,  milk  of  lime  and  caustic  soda  are  employed; 
for  waters  containing  an  excess  of  the  bicarbonates  of  lime 
and  magnesia,  milk  of  lime  in  slight  excess  is  used  to  advan- 
tage. 


CHAPTER  IX 
ANALYTICAL  CONTROL   IN  CANE-SUGAR   MANUFACTURE 

Determinations  Required.  Work  in  a  cane-sugar  house 
involves  the  analytical  control  of: 

The  Sugar  Cane. 

(a)  Cane. 

(6)  Cane   Juices:     First   Mill   Juice,    Mixed   Juices, 

Last  Mill  Juice,  Clarified  Juice, 
(c)  Syrup. 

Bagasse. 

Filter  Press  Work. 

(a)  Juices. 

(6)  Filter  Press  Cake. 

Sugars. 

(a)  Sugar. 

(6)  Fill  Mass. 

(c)  Molasses:  First  Molasses,  Exhaust  Molasses^ 

Waters. 

(a)  Condenser  Water. 

(6)  Waste  Water. 

(c)  Boiled-feed  Water. 

As  an  indication  of  the  determinations  which  should 
be  made,  the  following  scheme  is  suggested;  local  con- 
ditions will  of  course  determine  the  number  of  samples 
to  be  taken  and  submitted  to  analysis. 

164 


CONTROL  IN  CANE-SUGAR  MANUFACTURE      165 


Sample 

Determinations  to  be 
made 

Number  of  Determina- 
tions in  24  Hours 

SUGAR  CANE 

a.  Cane  fiber. 

Fiber 

1 

6.  Cane  juices 

Brix 

Sucrose 

24 

First  mill  juice 

Purity 

2 

Alkalinity  \ 

Acidity       / 

Brix               >> 

Sucrose 

24 

Purity 

2 

Mixed  juices 

Reducing  sugar 

Ash 

Alkalinity  \ 

1 

Acidity        / 

. 

Brix 

Sucrose 

24 

Last  mill  juice 

Purity 

2 

Alkalinity  \ 
Acidity        / 

2 

{Brix 

24 

Clarified  juice 

Sucrose 
Purity 

2 
2 

Alkalinity 

2      - 

Brix 

2 

Sucrose 

2 

c.  Syrup 

Purity 
Reducing  sugars 

2 
2 

Ash 

2 

Acidity 

2 

{Sucrose 

24 

BAGASSE 

Fiber 

2 

Dry  substance 

12 

FILTER-PRESS  WORK 

{Brix 

24 

a.  Juices 

Sucrose 
Purity 

2 
2 

1 

Alkalinity 

2 

b.  Filter-press  cake 

J           Sucrose 
\            Water 

2 
2 

SUGARS 

{Sucrose 

2 

a.  Sugar 

,  Reducing  sugars 
Water 

2 
2 

Ash 

2 

166 


SUGAR  ANALYSIS 


Sample 

Determinations  to  be 
made 

Number  of  Determina- 
tions in  24  Hours 

Brix 

Each  strike 

b.  Fill  mass 

Sucrose 

Each  strike 

I            Purity 

Each  strike 

(             Brix 

Each  strike 

c.  Molasses 

Sucrose 

Each  strike 

First  molasses 

Purity 

Each  strike 

Clerget 

Each  strike 

(              Brix 

Once  in  10  days 

Exhausted  molas- 

Sucrose 

Once  in  10  days 

ses 

Purity 

Once  in  10  days 

'Clerget 

Once  in  10  days 

WATERS. 

a.  Condenser  water  j 

Alpha-naphthol 
Sucrose  by  polariscopc 

Frequently 
As  needed 

b.  Waste  water 

Alpha-naphthol 
Sucrose  by  polariscope 

Frequently 
As  needed 

c.  Boiler-feed  water  > 

Alpha-naphthol 
Sucrose  by  polariscope 

Frequently 
As  needed 

The  testing  of  these  various  substances  and  products 
must  provide  for  a  determination  of  the:  Fiber,  Brix, 
Alkalinity,  Sucrose,  Clerget,  Purity,  Reducing  Sugars, 
Glucose  Ratio,  Ash,  Water,  Dry  Substance,  and  applica- 
tion of  the  Alpha-naphthol  reaction. 

Sugar  Cane.  The  choice  of  analytical  methods  to 
determine  the  sucrose  in  the  cane  lies,  to  a  certain  extent, 
between  direct  and  indirect  methods. 

The  former,  that  is  to  say,  the  direct  method,  is  really 
available  only  in  factories  employing  the  diffusion  process, 
or  for  the  determination  of  sucrose  in  individual  cane  stalks. 
In  ordinary  cane-sugar  house  work  however  one  or  the 
other  of  the  indirect  methods  must  be  employed. 

Select  at  least  two  canes  from  each  load  delivered  at 
the  factory.  Retain  10%  of  these  canes  at  the  end  of 
each  shift. 

Sucrose  in  Cane:  Direct  Method.  Although  there  are 
several  such  direct  methods  available,  probably  the  method 


CONTROL  IN  CANE-SUGAR  MANUFACTURE     167 

by  water  extraction  due  to  Zamaron,  best  answers  the  pur- 
pose.    This  method  involves  the  use  of: 

1.  A  metal  beaker  with  a  discharge  cock  at  the  bottom. 

2.  A  cylinder  made  of  wire  gauze,  small  enough  to  be 
placed  on  a  tripod  which  is  inserted  in  the  first  metal  vessel 
spoken  of,   and  permitting  some  space  to  exist  between 
the  bottoms  of  the  two. 

3.  A  perforated  metallic  disc  attached  to  a  rod,  the  disc 
to  be  of  such  dimensions  a-s  to  fit  well  into  the  gauze  cylinder. 

Underneath  vessel  No.  1  there  is  placed  a  liter  flask  in 
such  a  position  that  the  contents  of  this  vessel  No.  1  may 
be  readily  discharged  into  the  flask;  the  flask  itself  is  placed 
in  a  bath  through  which  cold  water  circulates.  Vessel 
No.  1  is  placed  over  a  Bunsen  burner,  or  other  heating 
device.  A  charge  of  50  grams  of  the  cane  pulp  is  intro- 
duced into  vessel  No.  2  which  is  inserted  in  vessel  No.  1. 
1,000  c.c.  of  pure  water  containing  enough  lime  to  make 
it  faintly  alkaline,  is  heated,  and  then  200  c.c.  of  this  water 
are  poured  on  the  pulp  contained  in  the  gauze  cylinder. 
Vessel  No.  1,  in  which  vessel  No.  2  is  inserted,  is  now  heated 
to  boiling.  This  boiling  is  continued  for  a  few  moments 
and  then  the  burner,  is  removed.  Next  the  contents  of 
these  vessels  are  run  into  the  liter  flask  in  which  a  few 
cubic  centimeters  of  neutral  lead  acetate  solution  have  been 
placed.  When  the  fluid  extract  has  passed  from  the  metal 
vessels  into  the  liter  flask  the  pulp  is  strongly  squeezed, 
and,  when  no  more  fluid  flows  out  of  the  stop-cock,  the 
same  is  closed,  and  the  treatment  with  the  hot  alkaline 
water  repeated.  This  time,  however,  only  150  c.c.  are 
used.  This  treatment  with  150  c.c.  of  the  hot  alkaline 
water  is  given  five  times  in  all.  After  the  final  treatment 
the  pulp  is  very  thoroughly  squeezed  in  order  to  remove 
as  much  liquid  from  it  as  possible.  Then  1  c.c.  of  basic 
lead  acetate  is  added  to  the  fluid  in  the  liter  flask,  its  con- 
tents are  made  up  to  the  mark,  well  shaken,  filtered,  and 
polarized  in  a  400  m.m.  tube.  The  readings  multiplied 


168  SUGAR  ANALYSIS 

by  2.605  are  taken  as  representing  the  percentage  of  sucrose 
in  the  cane. 

While  this  method  is  not  free  from  objections,  it  is 
possibly,  for  general  purposes,  the  best  direct  method  at 
present  known  for  the  determination  of  sucrose  in  the  cane. 

Sucrose  in  Cane:  Indirect  Methods:  Indirect  Method  I. 
This  is  based  on  adding  the  sucrose  extract  in  the  juice  and 
the  sucrose  retained  by,  i.e.,  lost  in  the  bagasse. 

The  sucrose  in  the  juice  is  determined  in  the  usual 
way  on  a  composite  sample  obtained  from  aliquot  parts 
of  each  measuring  tank.  These  samples  are  preserved 
during  collection  by  the  addition  of  one  part  of  formaldehyde 
to  5,000  parts  of  juice.  The  result  obtained  expresses 
per  cent  of  sucrose  in  100  parts  by  weight  of  the  juice. 

The  sucrose  in  the  bagasse  is  determined  according  to  the 
method  of  Zamaron  previously  described. 

The  sum  of  the  sucrose  found  in  the  juice  and  that  found 
in  the  bagasse  represents  the  sucrose  in  the  cane. 

Indirect  Method  II.  The  sucrose  found  in  the  mill 
juice  is  multiplied  by  a  factor. 

The  sucrose  is  determined  in  the  following  manner,  on 
a  sample  which  has  not  been  preserved  with  subacetate  of 
lead. 

Place  100  c.c.  of  the  juice  into  a  100-110  c.c.  flask,  clarify 
with  the  minimum  amount  of  subacetate  of  lead  solution, 
acidulate  with  acetic  acid,  make  the  volume  up  to  110  c.c. 
with  water,  mix  thoroughly,  filter  and  polarize  the  filtrate. 
The  percentage  of  sucrose  is  found  by  aid  of  the  Schmitz 
table.  In  accurate  work  the  error  caused  by  the  volume 
of  the  lead  precipitate  must  be  allowed  for.  The  sucrose 
in  the  cane  is  then  calculated  by  means  of  the  following 
formula: 

Percentage  of  sucrose  in  cane 

.     .   .     „  (100  -%  fiber) 
=  Percentage  of  sucrose  in  juiceX—    ~~IQQ —       •, 


CONTROL  IN  CANE-SUGAR  MANUFACTURE      169 

At  best,  the  figure  thus  obtained  is  for  several  reasons 
only  an  approximation.  Various  more  or  less  empirical 
factors  have  been  employed  for  the  purpose  in  different 
countries  at  different  times,  thus,  in  Egypt  at  one  time 
the  factor  0.87  was  in  use,  in  Java  0.85,  etc. 

To  obviate  these  difficulties,  Noel  Deerr  conceived  of 
an  "  absolute  juice  of  the  cane,"  which  term  he  defines 
to  mean  all  that  is  not  left  behind  on  extraction  by 
water. 

In  this  method  Deerr  uses  this  "  absolute  juice  "  as 
the  basis  for  multiplication  by  a  factor,  said  factor  to 
be  determined  by  each  factory  to  meet  its  own  con- 
ditions. 

Cane  Fiber  is  the  term  applied  to  that  part  of  the  sugar 
cane  which  remains  after  all  water  soluble  matter  has  been 
extracted  therefrom. 

From  10  to  20  kilograms  of  cane  are  crushed  in  a 
laboratory  mill,  and  about  75%  of  the  juice  is  expressed. 
The  resultant  bagasse  is  weighed,  cut  into  small  pieces,  and 
a  part  thereof  is  finely  ground. 

Of  this  pulp  take  20  grams  and  extract  first  with  cool 
water,  not  above  50°  C.,  to  insure  extraction  of  such  albumin- 
oids as  might  be  coagulated  by  hot  water;  then  treat  with 
water  of  about  70°  C.,  and  finally  with  water  near  the 
boiling  temperature,  until  all  soluble  matter  has  been  ex- 
tracted. This  entire  operation  should  be  completed  in 
about  45  minutes.  The  exhausted  bagasse,  i.e.,  the  fiber, 
is  then  removed  and  dried  to  constant  weight. 

The  result  is  calculated  as  follows: 

Cane  used 20  kgs. 

Bagasse 5   " 

Extracted  juice 15    " 

Fiber  in  20  grams  of  bagasse    9  grs.  =  45.0% 

Fiber  in  cane 


170  SUGAR  ANALYSIS 

This  value  can  also  be  found  in  the  following  way: 

Bagasse          =  25%  of  cane 
Fiber  =  45%  of  bagasse 

Fiber  in  cane  =  ^^5.  =  11. 25% 

Available  Sugar.  This  can  be  calculated  by  the  formulae 
of  Prinsen  Geerligs  or  taken  from  his  tables.* 

Cane  Juices.  The  samples  should  be  taken  from  the 
mills  preferably  by  some  continuous  sampling-device  or 
automatic  sampler,  and  formaldehyde  1:5000  added  as  a 
preservative. 

First  Mill  Juice.  After  mixing  thoroughly,  strain  the 
juice  through  a  fine  metallic  gauze  into  a  cylinder  which 
has  a  discharge  pipe  a  few  inches  above  its  bottom.  This 
pipe  is  kept  closed  while  the  heavy  suspended  impurities 
settle;  the  froth  will  of  course  rise  to  the  top.  When  the 
intermediate  portion  of  the  juice  is  clear  it  is  drawn  off 
for  analysis. 

Brix.  Note  the  temperature  of  the  juice  and  take 
the  reading  by  an  accurate  Brix  hydrometer,  making  this 
reading  on  the  surface  level  of  the  juice.  Correct  the  read- 
ing for  temperature  and  record. 

Alkalinity.  Prepare  a  sulphuric  acid  solution  for  titra- 
tion  of  such  a  strength  that  1  c.c.  corresponds  to  a  lime 
alkalinity  of  1  milligram.  Place  50  c.c.  of  the  juice  to  be 
tested  in  a  white  porcelain  dish,  use  litmus  paper  as  indicator, 
and  make  the  titration.  For  acidity  determinations  titrate 
with  alkali  solution  of  known  strength. 

Sucrose.  The  sample  on  which  this  determination  is 
made  is  obtained  by  taking  aliquot  samples  of  the  first  mill- 
juice  samples  taken  throughout  each  factory  shift.  These 
samples  are  to  be  kept  in  wide  mouthed  glass  jars,  and  are 
to  be  preserved  by  the  addition  of  mercuric  chloride, 
(corrosive  sublimate),  using  strength  1:5000. 

*  International  Sugar  Journal,  1912,  p.  274. 


CONTROL  IN  CANE-SUGAR  MANUFACTURE     171 

Place  100  c.c.  of  this  sample  in  a  100/110  c.c.  flask, 
add  3  to  5  c.c.  subacetate  of  lead,  complete  the  volume 
up  to  110  c.c.  with  distilled  water,  filter  and  polarize  in  a 
200  m.m.  tube.  Use  Schmitz's  table  for  determination  of 
the  sucrose  percentage. 

„     .,          Sucrose  X  100 
Punty:   , 


This  work  can  also  be  done  advantageously  by  Home's 
dry  lead  defecation  method  which  obviates  the  use  of  the 
110  c.c.  flask. 

Mixed  Juices.  Take  continuous  samples  from  each 
measuring  tank,  or  samples  equal  and  sufficient  in  amount, 
every  ten  minutes;  of  these  make  a  composite  sample 
each  hour.  Preserve  this  with  mercuric  chloride,  strength 
1:5000. 

Brix.  As  previously  directed. 

Alkalinity,  acidity. 

Sucrose. 

Purity.  " 

Reducing  Sugars.  The  sample  on  which  this  determina- 
tion is  made  is  obtained  by  reserving  25  c.c.  of  each  sample  of 
the  mixed  juices  procured  as  previously  described,  but  for 
this  determination  samples  preserved  with  formaldehyde 
can  not  be  used. 

Determination  of  the  reducing  sugars  is  carried  out  by 
volumetric  analysis,  by  means  of  Fehling's  Solution. 

Fehling's  Solution  is  prepared  as  follows  : 

Solution  No.  1.  Dissolve  34.639  grams  of  re-crystallized 
sulphate  of  copper  in  water,  making  the  solution  up  to 
500  c.c. 

Solution  No.  2.  Dissolve  173  grams  of  pure  crystallized 
Rochelle  salts  in  distilled  water.  Add  100  c.c.  of  a  50% 
solution  of  purest  sodium  hydroxide,  and  make  the  volume 
of  the  resultant  solution  up  to  500  c.c. 

Keep  Solutions  No.  1  and  No.  2  in  separate  flasks. 

Standardization  of  Fehling's  solution:     Take  9.5  grams 


172  SUGAR  ANALYSIS 

of  a  perfectly  dry,  chemically  pure  sucrose,  or,  in  default 
of  this,  use  for  the  purpose  the  stated  amount  of  the  highest 
grade  of  refined  sugar,  perfectly  dry.  Dissolve  with  75  c.c. 
of  distilled  water  in  a  100  metric  c.c.  flask.  When  complete 
solution  has  been  effected,  add  5  c.c.  of  hydrochloric  acid, 
having  a  specific  gravity  of  1.188,  mix  thoroughly,  insert 
a  thermometer  in  the  flask  and  put  the  same  on  a  water- 
bath  having  a  temperature  of  70°  C.  The  flask  and  its 
contents  are  kept  for  five  minutes  at  a  temperature  ranging 
between  67°  C.  and  70°  C.,  the  flask  being  frequently  gently 
shaken  during  this  time.  As  it  may  require  from  two  to 
five  minutes  to  raise  the  temperature  of  the  flask's  contents 
up  to  69°  C.,  the  entire  operation  may  take  from  seven  to 
ten  minutes;  it  must,  however,  never  exceed  ten  minutes. 

When  the  inversion  has  been  thus  achieved,  the  flask 
is  immediately  immersed  in  water  having  a  temperature 
of  20°  C.  The  thermometer  is  then  cautiously  removed 
from  the  solution,  any  solution  adhering  to  the  thermometer 
is  washed  back  into  the  flask,  its  contents  are  made  up  to 
exactly  100  c.c.,  well  mixed,  and  filtered.  Clarification 
with  basic  lead  acetate  is  not  permissible;  if  necessary, 
decolorization  must  be  effected  with  specially  prepared 
bone-black. 

As  9.5  parts  of  sucrose  on  inversion  yield  10  parts  of 
invert  sugar,  the  solution  prepared  as  above  described  will 
contain  exactly  10  grams  of  invert  sugar. 

50  c.c.  of  this  solution,  containing  5.0  grams  of  invert 
sugar,  are  measured  into  a  1000  c.c.  flask,  sodium  carbonate 
is  added  until  a  piece  of  red  litmus  paper  put  into  the  solu- 
tion, begins  to  turn  color.  When  this  occurs  the  contents 
of  the  flask  are  made  up  to  1000  c.c.  with  distilled  water, 
and  thoroughly  mixed.  Each  c.c.  of  this  solution  contains 
0.005  gram  of  invert  sugar. 

25  c.c.  of  Fehling's  Solution  No.  1,  and  25  c.c.  of  Fehling's 
Solution  No.  2,  are,  with  an  accurate  pipette,  measured 
into  a  deep  porcelain  dish  or  casserole;  to  this  50  c.c,  of 


CONTROL  IN  CANE-SUGAR  MANUFACTURE     173 

distilled  water  are  added  and  the  mixture  is  rapidly  raised 
to  the  boiling  point. 

The  inverted  sugar  solution  is  then  run  into  the  Fehling 
solution  from  a  burette  graduated  in  1/10  c.c.,  under  con- 
stant stirring  and  renewed  boiling,  until  all  of  the  cop- 
per in  the  copper  sulphate  solution  has  been  precipitated  as 
cuprous  oxide.  The  operator  is  warned  of  the  approach 
of  the  end  of  the  reaction  by  the  gradual  change  in  the 
color  of  the  solution;  the  blue  color  disappears  and  the 
solution  turns  colorless. 

The  end-point  of  this  reaction  is  determined  by  filter- 
ing a  few  drops  of  the  solution  through  a  minute  paper 
filter  into  a  very  dilute  solution  of  potassium  ferrocyanide 
(20  grams  in  1000  c.c.  water)  and  acetic  acid  of  10%  strength. 

If,  owing  to  the  formation  of  cupric  ferrocyanide,  a 
brownish-red  color  appears,  two-tenths  c.c.  more  of  the 
inverted  sugar  solution  are  added  to  the  Fehling  solution, 
the  same  is  again  boiled,  and  the  test  is  repeated.  These 
operations  are  continued  until  the  addition  of  a  few  drops 
of  the  inverted  sugar  solution  to  the  ferrocyanide  solution 
no  longer  produces  the  red  coloration. 

The  finding  should  always  be  confirmed  by  a  duplicate 
test. 

As  previously  stated,  1  c.c.  of  the  inverted  sugar  solu- 
tion used  contains  0.005  gram  of  invert  sugar. 

Suppose  that  49  c.c.  of  the  inverted  sugar  solution  have 
been  used  in  the  test,  then  to  effect  the  complete  reduction 
of  the  50  c.c.  of  the  Fehling  solution  employed,  there  have 
been  required:  49.0X0.005  =  0.245  gram  of  invert  sugar, 
and  this  measures  the  strength  of  the  Fehling  solution. 

The  determination  of  the  reducing  sugars  in  the  sample  of 
mixed  juices  to  be  analyzed,  is  carried  out  precisely  as  above 
described  for  the  standardization  of  the  Fehling  solution. 

Take  20  c.c.  of  the  composite  juice  sample,  place  in 
a  100  c.c.  flask,  make  the  volume  up  to  100  c.c.,  filter,  and 
run  the  filtrate  from  a 'burette  into  the  Fehling  solution. 


174  SUGAR  ANALYSIS 

The  amount  of  reducing  sugars  is  obtained  from  Table 
XII. 

Glucose  Ratio.  The  reducing  sugars  found,  multiplied 
by  100,  and  this  product  divided  by  the  sucrose,  is  known 
as  the  glucose  ratio. 

Ash.  This  determination  is  made  on  10  grams  of  the 
mixed  juices.  Evaporate  carefully  to  dryness,  moisten 
with  20  drops  of  dilute  sulphuric  acid  (1:  1),  pour  a  little 
ether  over  the  contents  of  the  dish  and  ignite.  This  treat- 
ment yields  a  porous  carbonized  mass,  and,  in  a  great 
measure,  avoids  danger  of  loss.  When  all  gases  have 
burned  off,  place  the  dish  in  a  muffle,  keep  the  same  at  a 
dull-red  heat  until  the  sample  has  been  completely  ashed, 
then  cool  and  weigh.  Subtract  10%  from  the  weight 
found  and  record  the  result  as  total  ash. 

Water.  For  rapid  determinations,  take  10  grams  of 
the  sample,  mix  intimately  with  perfectly  dry  ground  glass 
or  powdered  quartz.  Heat,  preferably  in  a  vacuum  stove, 
at  a  temperature  not  to  exceed  103°  C.,  to  constant  weight. 
Should  the  last  weighing  made  show  a  slight  gain  over  the 
weighing  immediately  preceding,  accept  the  latter  as  the 
true  weight,  for  an  increase  in  weight  indicates  incipient 
oxidation. 

For  very  accurate  work  .the  following  method  advocated 
by  Paul  Poetschke  is  recommended.  To  carry  this  into 
effect  place  10  grams  of  dry  pure  quartz  sand  and  a  short 
stirring  rod  into  a  100  c.c.  beaker.  Dry  thoroughly  at 
100°  C.,  cool  and  weigh.  Introduce  about  5  grams  of 
the  sample,  mix  with  the  sand,  and  gradually  add,  while 
stirring,  10  c.c.  of  absolute  alcohol.  Evaporate  to  dryness 
on  a  water-bath,  again  add  10  c.c.  of  the  alcohol,  and  repeat 
the  evaporation  to  dryness  as  before.  After  the  second 
portion  of  alcohol  has  been  evaporated,  place  the  beaker 
in  an  air-bath  and  dry  for  2J  hours  at  100°  C.  Cool  in  a 
desiccator  and  weigh.  Repeat  the  heating  at  100°  C. 
for  one  hour,  and  again  weigh,  to- learn  whether  the  drying 


CONTROL  IN  CANE-SUGAR  MANUFACTURE     175 

is  completed.  Ordinarily  2*  hours  will  prove  sufficient 
for  the  operation. 

The  quartz  sand  used  is  prepared  in  the  well-known 
manner  by  digesting  with  strong  hydrochloric  acid,  washing, 
drying  and  igniting.  The  alcohol  used  must  of  course  be 
pure,  and  leave  no  appreciable  residue  on  evaporation. 

Last  Mill  Juice  and  Clarified  Juices.  The  determina- 
tions to  be  made  are  the  following: 

Brix.          As  previously  directed. 

Sucrose. 

Purity. 

Syrup,  is  the  term  assigned  to  the  purified  cane  juice  after 
concentration.  Samples  equal  in  amount  are  to  be  taken 
from  every  settling  tank,  and  of  these  a  composite  sample 
is  made,  and  analyzed  once  in  each  shift.  The  analytical 
determinations  to  be  carried  out  are  the  following: 

Brix.  As  previously  directed 

Alkalinity  or  acidity. 

Sucrose. 

Purity. 

Reducing  Sugars: 

Ash. 

Bagasse,  or  Megass,  is  the  refuse  of  the  cane  after  crushing. 
Its  essential  constituents  are  cellulose-fiber  and  wood  gum. 

Saturation  is  the  amount  of  water  sprayed  upon  the 
bagasse  in  grinding.  The  water  so  used  is  measured,  its 
temperature  is  taken,  correction  for  temperature  is  made 
to  reduce  it  to  its  corresponding  volume  at  4.0°  C.,  at 
which  temperature  water  attains  its  maximum  density. 

Pounds. 

1  cubic  ft.  of  water  at    4°  C.  weighs       62.427 
1  "  "  20°  C.      "  62.32 

1  "  "  30°  C.       ?.'  62.16 

Percentage  Saturation  of  the  cane  weight 

=  62.427Xcu.ft.  of  water  at  4°  C.XlOO 
Weight  of  Canes  in  pounds 


176  SUGAR  ANALYSIS 

Small  samples  of  bagasse  should  be  frequently,  if  not  con- 
tinuously taken,  placed  in  galvanized  iron  cans,  sterilized  with 
a  few  drops  of  formaldehyde,  and  analysis  made  every  hour. 

Sucrose.  Cut  or  shred  the  bagasse  as  rapidly  as  possible, 
as  it  very  quickly  changes  its  moisture  content  on  exposure 
to  air.  50  grams  of  this  comminuted  bagasse  are  boiled 
with  500  c.c.  of  water,  8  c.c.  of  basic  lead  acetate  solution 
and  10  c.c.  of  a  5%  sodium  carbonate  solution  in  a  metallic 
beaker  provided  with  a  reflux  condenser.  After  boiling 
for  one  hour,  cool  and  weigh  beaker  with  its  contents. 
Filter  and  polarize  nitrate  in  a  400  m.m.  tube. 

The  method  of  calculation  is  illustrated  by  the  following 
example  : 

Fiber  in  bagasse  (assumed)  =  45% 

Fiber  in  bagasse  =  22.5  grams 

luu 

Weight  of  beaker,  bagasse  and  water       =  750 
Weight  of  beaker  =250.0       " 

Weight  of  bagasse  and  water  =  500.0       " 

Weight  of  fiber  in  bagasse  =   22.5       " 

Weight  of  solution  =477.5       " 

Polarization  of  solution  in  400  m.m.  tube  =  5.0°  Ventzke. 

5.0 


This,  according  to  the  Schmitz  table  =  1.27%  sucrose. 
This  value,  divided  by  two,  in  order  to  reduce  to  a  read- 
ing in  200  m.m.  tube  =  0.635%  sucrose  in  the  solution. 
The  weight  of  this  solution  =  477.  5  grams,  hence,  there 

477.5X0.635 

are  --  Tnn  -  =3.03  grams  sucrose  in  the  bagasse. 
luu 

As  50  grams  of  bagasse  were  used  for  the  analysis,  this 
corresponds  to  6.06%  sucrose  in  the  bagasse. 

Fiber.  Fiber  is  the  cellular  woody  residue  of  the  cane 
after  this  has  been  exhausted  with  water. 


CONTROL  IN  CANE-SUGAR  MANUFACTURE     177 

Take  50  or  100  grams  of  the  material  and  make  the 
determination  as  previously  described. 

If  desired,  a  check  on  the  analytical  result  found  may 
be  made  by  the  formulae: 

Per  cent  Juice  Solids  in  bagasse 

Per  cent  sucrose  in  bagasse  X 100 
Purity  coefficient  of  last  mill  juice 

Per  cent  Fiber  =  100— (per  cent  juice  solids  in  bagasse+per 

cent  water  in  bagasse) 

This  calculation  involves  the  assumption  that  the 
purity  coefficient  of  the  last  mill  juice  and  that  of  the  bagasse 
juice  are  identical.  Example: 

Per  cent  sucrose  in  bagasse  =  5% 

Purity  coefficient  of  last  mill  juice  =  72 

5  OX  100 
Per  cent  juice  solids  in  bagasse       =  -1-— =6.94% 

Per  cent  water  in  bagasse  =44.06% 

Per  cent  fiber  =  100-  (6.94+44.06)  =49.0% 

Water.     As  previously  directed. 

Dry  Substance  in  Bagasse.  Chop  up  finely,  and  as 
quickly  as  possible,  50  grams  of  bagasse.  Place  in  a  tared 
vessel — shallow  trays,  or  tubes  made  of  gauze  and  provided 
with  gauze  net  caps,  and  dry  to  constant  weight  at  from 
95°  C.  to  105°  C.  Cool  in  desiccator  over  sulphuric  acid, 
and  weigh  quickly. 

The  loss  in  weight  found  represents  the  water  in  the 
bagasse.  The  difference  between  100  and  this  value  is  the 
dry  substance. 

Filter-Press  Work.  Juice.  The  analytical  determina- 
tions to  be  made  are  the  following: 

Brix.  As  previously  directed. 

Alkalinity.  "  " 

Sucrose.  "  ll 

Purity.  <*  " 


178  SUGAR  ANALYSIS 

Cake.  Samples  must  be  taken  from  at  least  three  press 
cakes,  preferably  five  samples  should  be  taken  from  each 
cake,  one  from  the  center  of  the  cake,  and  one  from  each 
corner.  The  analytical  determinations  to  be  made  are  the 
following : 

Sucrose.  Weigh  out  25  grams — to  allow  for  the  insol- 
uble matter  present.  Work  up  with  water  into  cream, 
wash  into  a  100  c.c.  flask,  add  basic  acetate  of  lead  solu- 
tion, from  2  to  4  c.c. — sufficient  to  clarify — make  the  solu- 
tion up  to  100  c.c.  in  volume,  filter  and  polarize  the  filtrate 
in  a  200  m.m.  tube.  The  polarization  found  expresses  the 
percentage  of  sucrose  in  the  filter  press  cake. 

Water.  5  grams  are  to  be  used  for  this  determination 
which  is  to  be  carried  out  as  previously  directed. 

Sugars.  All  samples  must  be  systematically  taken; 
a  thorough  mixing  of  such  samples  before  analysis  is  of 
course  imperative.  The  analytical  determinations  to  be 
made  are  the  following: 

SUGAR:     Sucrose.     As  previously  directed. 

Clerget.  Weigh  out  26.0  grams  of  the  sample,  and 
determine  the  polarization  as  usual.  Of  the  solution  take 
50  c.c.  for  inversion,  or,  weigh  out  13.0  grams  of  the  sample 
separately.  Dissolve  with  about  75  c.c.  of  water  in  a  100 
c.c.  flask;  after  complete  solution  has  been  effected  add 
5  c.c.  hydrochloric  acid  (sp.gr.  1.188),  containing  38  per 
cent  HC1.  Heat  quickly,  in  two  or  three  minutes,  on  a 
water-bath  up  to  between  67°  and  70°  C.  Then  keep  the 
temperature  of  the  solution  for  five  minutes  as  close  to 
69°  C.  as  possible,  while  agitating  constantly.  Cool  quickly 
to  20°  C.,  fill  with  distilled  water  up  to  the  100  c.c.  mark, 
and  polarize  in  a  tube  provided  with  an  accurate  thermom- 
eter. The  temperature  at  which  the  reading  is  taken 
should  be  20°  C.,  and  that  of  the  saccharimeter  should 
also  be  at  20°  C. 

The  use  of  subacetate  of  lead  for  clarifying  purposes 
is  not  permissible  as  this  reagent  affects  the  rotatory  power 


CONTEOL  IN  CANE-SUGAB  MANUFACTURE     179 

of  invert  sugar.     If  a  decolorant  must  be  used,  specially 
prepared  bone-black  should  be  employed. 

The  result  is  calculated  as  follows: 
Let    R  =  Sucrose. 

$  =  Sum   of  the   two   polarizations   before   and   after 

inversion,  the  minus  sign  being  ignored. 
^Degrees   Centigrade    at   which   the    polarizations, 
before  and  after  inversion  were  observed, 

100X5 

tnen  R = 


142.66- (0.5X0' 

The  two  polarizations — the  one  before,  the  other  after 
inversion,  must  always  be  made  at  one  and  the  same  tem- 
perature, because  the  optical  rotation  value  of  invert  sugar 
is  materially  influenced  by  temperature-changes.  As  the 
International  Commission  has  accepted  20°  C.  as  the 
standard  temperature,  20°  C.  is  to  be  used  in  the  above 
determinations  and  formula. 

If  no  other  optically  active  body  besides  the  sucrose 
is  present,  the  Clerget  polarization  will  of  course  return 
a  value  equivalent  to  the  direct  polarization  value  originally 
found .  Example : 

Polarization  of  normal  weight  before  inversion,  at  20° 
C.  =  87.5° 

Polarization  of  half  normal  weight  after  inversion,  at 
20°C.=  -14.3° 

-14.3X2  87.5  100X116.1 


-28.6  28.6  142.66-10 


p_  ii6io 

"132.66" 


Reducing  Sugars.     As  previously  directed. 

Water. 

Ash. 


180  SUGAR  ANALYSIS 

FILL  MASS.  Fill  mass,  or  massecuite,  is  the  term  given 
to  the  crystalline  magma  obtained  by  boiling  sugar  solu- 
tions in  the  vacuum  pan.  Distinctive  names,  such  as 
first,  second,  mixed,  etc.  fill  mass,  are  often  assigned  to 
fill  masses  boiled  from  specific  products. 

Thus,  the  designation  first  fill  mass  is  often  employed 
to  denote  the  product  boiled  entirely,  or  at  least  in  greater 
part,  from  syrup.  Purged  second  sugars  are  often  added  to 
the  first  fill  mass  and  so  appear  as  centrifugal  sugars. 

By  second  fill  mass  there  is  generally  understood  the 
product  obtained  by  boiling  a  small  amount  of  syrup 
together  with  the  molasses  from  a  first  fill  mass. 

During  the  discharge  from  the  vacuum  pan  several  sam- 
ples of  each  fill  mass  should  be  taken,  as  strikes  do  not  run 
uniformly.  These  various  samples  should  be  made  up  into 
a  composite  sample  and  the  analysis  made  on  this.  When- 
ever samples  are  obtained  from  crystallizers  or  mixers, 
these  should  be  taken  only  after  the  mass  has  undergone  a 
thorough  mixing. 

The  analytical  determinations  to  be  made  on  fill  mass 
samples  are  the  following: 

Brix.      As  previously  directed. 

Sucrose.  " 

MOLASSES.  The  more  or  less  impure  sugar  solutions 
spun  off  from  the  fill  mass  in  the  centrifugal  machines,  are 
known  as  molasses;  the  molasses  lowest  in  purity  is  termed 
final  or  exhausted  molasses. 

The  sampling  of  molasses,  as  well  as  the  taking  of  its 
weight,  must  be  conducted  with  great  care,  as  molasses 
will  readily  imprison  air,  and  this,  of  course,  tends  to  reduce 
the  weight  of  the  molasses  per  unit  volume  to  a  con- 
siderable degree. 

Brix.  To  250  grams  of  the  sample  add  250  grams  of 
water,  and  bring  into  perfect  solution,  however,  without 
the  aid  of  heat.  Determine  the  degrees  Brix  of  this  solu- 
tion, multiply  by  two,  and  then  only  correct  for  tempera- 


CONTROL  IN  CANE-SUGAR  MANUFACTURE     181 

ture,  because  the  coefficient  of  expansion  of  the  non-sugars 
in  cane-sugar  molasses  varies  from  that  of  sucrose  for  which 
the  tables  were  calculated,  but  which  difference  is  allowed 
for  by  proceeding  with  the  calculation  as  above  directed.* 

Sucrose.  Weigh  out  the  normal  weight  of  the  above 
solution,  place  in  a  100  c.c.  flask,  clarify  with  basic  lead 
acetate  solution,  using  the  smallest  amount  possible  to  effect 
the  decolorization,  bring  the  volume  up  to  100  c.c.,  filter  and 
polarize.  If  the  solution  is  sufficiently  light  in  color  use 
the  200  m.m.  tube  and  multiply  the  reading  found  by  two; 
if  the  100  m.m.  tube  must  be  employed,  the  reading  observed 
on  the  polariscope  must  be  multiplied  by  four,  and  the 
resulting  value  recorded  as  sucrose. 

Purity.  Having  determined  the  polarization  of  the 
normal  weight,  and  the  degree  Brix  of  the  sample  corrected 
for  temperature,  use  the  formula: 

Polarization  X 100 

Purity  =  — ^—          -r,  . 

Degrees  Brix 

Example:  Polarization  =40.0 

Corrected  Brix       =51.0 
40.0X100     -Q 
-5LO-  =7SA 

Clerget.  The  direct  polarization  and  the  polarization 
after  inversion  should  be  carried  out  on  portions  of  one 
and  the  same  solution;  for  this  reason  two  or  three  times 
the  normal  weight  of  the  molasses  should  be  dissolved  in 
500  c.c.  of  water.  The  determination  is  then  carried  out 
as  previously  directed. 

Waters.  Condenser  Water.  The  term  condenser  water, 
or  circulation  water,  is  applied  to  the  water  which  serves 
to  condense  the  vapors  coming  from  the  vacuum  concen- 
tration apparatus. 

*  Prinsen  Geerligs,  Methods  of  Chemical  Control  in  Cane  Sugar 
Factories,  Altrincham,  1905,  p.  15. 


182  SUGAR  ANALYSIS 

Samples  of  this  water  should  be  frequently  and  system- 
atically, if  possible  automatically,  taken  from  the  tail  pipes 
and  condensers  of  all  vacuum  concentration  apparatus. 

The  analytical  determinations  called  for  are  the  follow- 
ing: 

Brix.    As  previously  directed. 

Sucrose.  As  the  amount  of  sucrose  which  may  normally 
be  expected  in  condenser  waters  is  very  small,  a  delicate 
test  for  its  presence  must  be  employed. 

Such  a  test  is  afforded  by  the  alpha-naphthol  reaction 
of  Molisch,  whose  reagent  consists  of  a  20%  alcoholic  solu- 
tion of  alpha-naphthol.  2  c.c.  of  the  water  which  is  to  be 
tested  for  the  presence  of  sucrose,  are  introduced  into  a 
test-tube,  and  five  drops  of  the  Molisch  reagent  are  added. 
Then,  10  c.c.  of  chemically  pure  concentrated  sulphuric 
acid  are,  by  means  of  a  pipette,  allowed  to  flow  to  the  bot- 
tom of  the  test-tube.  This  test,  as  has  been  said  before, 
is  a  very  delicate  one.  If  any  appreciable  quantity  of 
sucrose  is  present,  a  zone  of  color  appears  at  the  line  of 
contact  of  the  two  fluids.  If  the  contents  of  the  test-tube 
are  thoroughly  mixed  by  shaking,  the  solution  will  show 
a  pale  violet  coloration,  even  if  only  0.001%  of  sucrose 
is  present;  0.01%  of  sucrose  gives  a  bright  claret  color,  and, 
if  as  much  as  0.1%  of  sucrose  is  present,  the  entire  solution 
darkens  and  turns  opaque. 

Nitric  acid  interferes  with  this  reaction,  hence,  both 
the  sulphuric  acid  and  the  aqueous  solution  to  be  tested 
must  be  entirely  free  from  nitric  acid;  ammonia,  lime  salts 
and  most  organic  impurities  to  be  found  in  water,  do  not 
interfere  with  this  reaction. 

If  the  alpha-naphthol  reaction  indicates  any  appreciable 
amount  of  sucrose  in  a  condenser,  or  other  waste  water, 
the  polarimetric  determination  of  the  sucrose  must,  in 
every  instance,  be  made. 

Such  polarimetric  observation  is  carried  out  in  the 
following  manner. 


CONTROL  IN  CANE-SUGAR  MANUFACTURE     183 

The  zero  point  of  the  polariscope  is  determined  with 
the  utmost  care;  for  this  purpose  it  is  best  to  employ  the 
400  m.m.  tube  filled  with  perfectly  pure  distilled  water. 
When  the  zero  point  has  thus  been  accurately  determined 
and  fixed,  the  water  to  be  examined  is  put  into  the  400 
m.m.  tube,  and  a  careful  set  of  readings  taken.  In  inter- 
preting such  readings  the  limit  of  sensibility  of  the  polari- 
scope employed  must  of  course  be  carefully  taken  into 
account. 

Purity.     As  previously  directed. 

Waste  Waters.  A  continuous,  preferably  an  automatic 
sampling  of  all  waste  waters  is  of  the  utmost  importance 
in  order  to  detect  and  to  guard  against  excessive  and  often 
wholly  unsuspected  loss  of  sucrose  through  leaks  and  over- 
flows. The  analytical  determinations  to  be  made  are: 

Brix.     As  previously  directed. 

Sucrose.  Alpha-naphthol  test  as  previously  directed; 
polarimetric  test  as  directed. 

Boiler-Feed  Water.  The  danger  of  having  sugar  in 
the  boiler-feed  water,  apart  -from  the  loss  of  sucrose  itself, 
is  so  well  understood,  that  it  need  not  be  here  specifically 
referred  to.  As  a  safeguard,  frequent  sampling  of  the 
boiler-feed  water  is  necessary.  The  analytical  determina- 
tions to  be  carried  out  are  as  follows: 

Alkalinity.  A  sudden  drop  in  alkalinity  indicates  con- 
tamination by  sugar. 

Sucrose.  Alpha-napthol  test  as  previously  directed; 
polarimetric  test  as  previously  directed. 

Calculations.  While  direct  measurements  and  deter- 
minations are  always  preferable  to  values  calculated  in- 
directly from  analytical  or  other  data,  the  use  of  certain 
calculations  is  unavoidable  and  must  be  made  as  a  matter 
of  daily  record. 

To  guard  against  misunderstanding  a  few  explanatory 
words  concerning  the  terms  as  commonly  used  and  under- 
stood are  given  in  connection  with  the  formulae  by  which 


184  SUGAR  ANALYSIS 

the  values  referred  to  are  calculated.  For  the  summation 
of  these  the  writer  is  especially  indebted  to  the  work  of 
Prinsen  Geerligs. 

Cane  Formulae.  Sucrose  in  100  Cane.  As  a  correct 
sampling  of  cane  is  not  possible,  owing  to  its  nature,  the 
amount  of  sucrose  in  it  is  determined  by  aid  of  a  factor 
by  which  the  desired  value  is  calculated  from  the  amount 
of  sucrose  in  the  first  mill  juice.  This  factor  varies  for 
different  fiber  and  different  extraction,  it  ranges  from  about 
0.84  to  0.86,  but-  is  usually  taken  as  0.85. 

(1)  Sucrose  in  100  Cane  =  Sucrose  in  100  parts  of  first 
mill  juice  X  factor.     This  formula,  however,  merely  affords 
an  approximation.     The  actual  determination  of  the  fac- 
tor to  be  used  can  be  effected  by  crushing  a  known  weight 
of  cane  in  the  mills,  analyzing  the  first  mill  juice,  obtain- 
ing the  weight  of  the  bagasse,  and  determining  the  amount 
of  sucrose  it  has  retained. 

Sucrose  Extracted  in  100  Cane.  This  corresponds  to 
the  sucrose  in  juice  in  100  cane. 

(2)  Sucrose  extracted  in  100  cane  =  Sucrose  in  100  parts 
of  cane  — sucrose  in  100  parts  bagasse.     This  value  is  of 
course  also  only  an  approximation  value,   as  it  embodies 
the  approximate  value  obtained  by  Formula  (1). 

Weight  of  Available  Sugar.  This  represents  the  estimated 
yield  of  sugar  based  on  the  analytical  data. 

(3)  Weight  of  available  sugar  =  Weight  of  sucrose  entered 

in  juiceX  ( 1-4  — ~ — r— )  * 
\          Purity/ 

(4)  Available  sugar  in  100  cane  =  Sucrose  extracted  in 

100  cane  X  (1.4 --5^? 
\          Purity 

*  For   derivation   of   this   formula   and   for    values   of  the   factor 

40 

1.4—          -  for  various  degrees  of  purity  between  77  and  93,  confer 
purity 

Prinsen  Geerligs,  Methods  of  Chemical  Control  in  Cane-Sugar  Fac- 
tories, Altrincham,  1905. 


CONTROL  IN  CANE-SUGAR  MANUFACTURE      185 

Calculated  Weight  of  Cane  Crushed.  If  all  the  cane 
delivered  to  the  factory  per  day  is  crushed  the  same  day, 
this  cane  delivery  weight  of  course,  represents  also  the 
weight  of  the  cane  crushed.  Frequently,  however,  this 
is  not  the  case,  and  then  the  value  sought  is  found — approx- 
imately only,  however, — by  the  formula: 

(5)  Weight  of  cane  crushed 

_  Weight  of  sucrose  entered  in  juice 
Sucrose  extracted  in  100  cane 

Juice  Formulae.  Weight  of  Sucrose  Entered  in  Juice. 
This  value  is  the  fundamental  factor  of  control  in  the  work- 
ing of  a  factory,  and  no  care  must  be  spared  to  get  it  as 
accurate  as  possible,  whether  the  juice  be  measured  or 
weighed. 

(6)  Weight  of  Sucrose  entered  in  juice  =  Weight  of  mixed 

.   .        Sucrose  in  100  parts  mixed  juice 
julce>  -w- 

Sucrose  in  Normal  Juice.  Normal  juice  is  the  juice  as 
it  actually  occurs  in  the  cane  and  would  be  exemplified  by 
juice  extracted  by  all  of  the  mills  without  any  maceration. 
In  practice  this  can  not  be  obtained. 

In  some  factories  the  juice  from  the  first  mill  is  con- 
sidered as  normal  juice.  This,  however,  is  improper,  for 
the  juices  from  all  the  other  mills  are  inferior  in  quality  to 
first  mill  juice.  It  has  therefore  become  customary  to  make 
certain  assumptions,  and  to  make  the  following  calcula- 
tions. 

(7)  Sucrose  in  normal  juice 

_Brix  of  first  mill  juice X Purity  of  mixed  juice 
100 

Extraction.  This  represents  the  ratio  between  the 
sucrose  extracted  by  the  mills,  and  the  total  amount  of 
sucrose  in  the  cane. 

/o\  -^  4.      x-         Sucrose  extracted  in  100  cane 

(8)  Extraction  =  -5—      — -. — -7^—  —  X100 

Sucrose  in  100  parts  of  cane 


186  SUGAK  ANALYSIS 

If,  for  instance,  there  are  known  the: 

Percentage  of  sucrose  in  cane       =  13  .  00% 
11  bagasse  =  4.30% 
fiber       "  cane       =12.00% 
bagasse  =45.  00% 


fiber       " 
" 


-j  o 

then   the   Bagasse   per   100  cane  =  -^::-    --  =  24.45 


24  45x45 
and  the  Sucrose  in  bagasse  per  100  cane=—  ^  —  -^-  =  0.92 


Sucrose  in  juice  per  100  cane  =  13  .  00 

-  0.92 


12.08 


Extraction  =      '  =  92.92% 

lo.U 


J.  H.  Morse  calls  attention  to  the  fact  that  the  term 
extraction  is  used  in  a  different  sense  in  various  localities. 
Thus,  in  Cuba,  extraction  indicates  the  yield  of  sugar;  in 
Louisiana  it  signifies  the  per  cent  of  juice  by  weight  extracted 
from  the  cane;  in  the  Hawaiian  Islands  this  term  is  given 
to  the  sucrose  in  the  juice  compared  with  the  sucrose  in 
the  cane.* 

Maceration  Dilution.  Maceration,  saturation,  inhibi- 
tion, signifies  the  water  added  to  the  bagasse  on  the  millr; 
dilution  means  the  amount  of  water  which  is  added  to  100 
parts  of  normal  juice.  It  is  figured  by  the  formula 

(9)  Maceration  dilution 

Brix  of  first  mill  juice  _ 

~^pr    .          » : i    .     . 

Brix  of  mixed  juice 
*  Calculations  used  in  Cane-Sugar  Factories,  1904, 


CONTROL  IN  CANE-SUGAR  MANUFACTURE      187 

Percentage  of  Normal  Juice  Extracted  from  100  Cane. 
This  value  is  only  approximate;  it  is  calculated  by  the 
formula: 

(10)  Percentage  of  normal  juice  extracted  from  100  cane 

Sucrose  extracted  in  100  cane 
"Sucrose  in  100  parts  of  first  mill  juice 

Weight  of  Sucrose  Returned  to  Juice.  When  sugars  are 
worked  over  in  the  factory  it  is  necessary  to  redetermine 
their  weight  and  analysis. 

(11)  Weight   of  returned   sucrose  =  Weight  of  returned 

.,  Sucrose  in  100  returned  sugar 
sugar  X-       JQQ— 

Sucrose-loss  Formulae.  Sucrose  Lost  in  Bagasse  on  100 
Cane.  Of  approximate  value  only,  as  it  is  assumed  that 
the  juice  is  entirely  free  from  fiber.  Calculated  by  the 
formulae : 

(12)  Sucrose   lost  in  bagasse   in  100  cane  =  Sucrose  in 

Fiber  on  100  parts  of  cane   \ 


/  F 
100  parts  of  bagasse  (  ^ 


Fiber  in  100  parts  of  bagasse/ 

(13)  Weight  of  sucrose  lost  in  bagasse  =  Weight  of  cane 

,     ,  ^,  Sucrose  lost  in  bagasse  on  100  parts  of  cane 
crushed  X— 

1UU 

(14)  Weight  of  sucrose  lost  in  filter-press  cakes  =  Weight 

Sucrose  in  100  cakes 
of  press  cakes  X 


CHAPTER  X 
ANALYTICAL  CONTROL  IN  BEET-SUGAR  MANUFACTURE 

Determinations  Required.  The  analytical  determina- 
tions to  be  made  in  the  systematic  control  of  beet-sugar 
houses  are  as  follows;  the  number  of  samples  to  be  taken 
for  analysis  must  of  course  be  governed  by  local  con- 
ditions. 


Sample. 

Determinations  to  be 
Made. 

Number  of  Determinations 
in  24  Hours. 

I.  Beets 

Polarization 

1 

f 

Polarization 

] 

a.  Fresh  cosettes         \ 

Invert  sugar 

8 

( 

Dry  substance 

J 

b.  Exhausted  cosettes 

(       Polarization 
\     Dry  substance 

}        » 

c.  Dry  cosettes 

Polarization 

Brix 

II.  Diffusion  and 

Polarization 
Invert  sugar 

24 

press-juices 

Acidity 

Coagulation  value 

Brix 

Polarization 

III.  Diffusion  waters 

Invert  sugar 

8 

Acidity 

Coagulation  value 

IV.  Thin    juices,    non- 
saturated  and 
saturated 

(              Brix              } 
1       Polarization        1 
Color 
Alkalinity         J 

Non-saturated  juice  24 
Saturated  juice  24 
Continuous  saturation 
48 

Brix 

Polarization 

V.  Thick  juices 

Invert  sugar 
Dry  substance 

48 

Color 

Alkalinity 

188 


CONTROL  IN  BEET-SUGAR  MANUFACTURE       189 


Sample. 


Determinations  to  be 
Made. 


Number  of  Determinations 
in  24  Hours. 


VI.  Press  cakes 


VII.  Fill  mass 
a.  First  Products 


b.  After  products 


VIII.  Raw  sugars 
First  products  and 
after  products 


IX.  Molasses 


X.  Cattle  food 

XL  Waters 

a.  Condenser  water 

b.  Waste  water 

c.  Boiler  feed  water 


Polarization 

Alkalinity 

Polarization 

Invert  sugar 

Ash 

Lime 

Alkalinity 

Water  (dry  substance) 

Brix 

Polarization 
Invert  sugar 

Lime 

Color 

Alkalinity 

Water  (dry  substance) 

Polarization 

Invert  sugar 

Water 

Ash 
Alkalinity 

Brix 

Polarization 

Apparent  purity 

Invert  sugar 

Water 

Ash 
Water 

Ash 
Crude  protein 

Crude  fiber 
Ether  extract 

Sucrose 

Invert  sugar 

a-naphthol  test 

Polarization 
a-naphthol  test 

Polarization 

a-naphthol  test 

Polarization 


Each  strike 


Each  strike 


Each  lot 


I  Take    2    samples 
I  daily    and    make    a 

composite     sample 

for  each  week 


In  the  preparation  of  this  chapter  free  use  has  been 
made  of  the  directions  issued  by  the  Verein  der  Deutschen 


190  SUGAR  ANALYSIS 

Zuckerindustrie.  For  permission  to  do  this  the  writer's 
cordial  acknowledgements  are  due  Professor  Dr.  Alexander 
Herzfeld,  Berlin. 

Sugar-Beets.  It  is  extremely  difficult  to  get  a  representa- 
tive sample  of  the  beets  as  delivered  at  a  factory.  If  such 
is  demanded,  it  is  perhaps  most  convenient  to  take  the  beets 
on  which  the  mud  has  been  determined,  select  say  every 
tenth  beet  of  the  lot,  scour  well,  cut  off  the  top  and  roots 
and  then  cut  segments  from  the  beet  and  grind  to  a  pulp. 

A  far  better  average  sample  can  however  be  obtained 
from  fresh  beet-cosettes.  These  are  taken  at  short  inter- 
vals of  time,  or,  better  still,  continuously — placed  in  a  closed 
vessel,  and,  after  being  thoroughly  mixed,  submitted  to 
analysis  at  least  every  three  hours. 

The  sample  must  be  reduced  to  a  very  fine  pulp  before 
analysis  and  this  is  done  by  means  of  rasps,  files,  slicers, 
grinders,  etc.,  of  which  a  number  of  different  kinds  are 
available. 

FRESH  COSETTES.  Polarization.  Employ  the  method 
of  hot  aqueous  digestion.  Pass  about  1  kilogram  several 
times  through  slicing  machine,  weigh  out  26.0  grams  of 
this  pulp  on  a  small  tin  scoop,  place  latter  with  its  contents 
into  a  dry  metallic  beaker  provided  with  a  cap,  pour  into 
this  beaker  177  c.c.  basic  lead  acetate  solution  (25  c.c. 
basic  lead  acetate  per  liter),  close  beaker,  shake  well,  heat 
30  minutes  at  75°-80°  C.,  cool,  again  shake  thoroughly, 
filter  and  polarize. 

Invert  Sugar.  20  c.c.  of  the  above  solution  are  boiled 
for  2  minutes  with  J  c.c.  Fehling's  solution.  If  the  filtrate 
remains  blue,  or  if  after  deleading  (cold)  with  a  few  drops 
of  a  bicarbonate  of  soda  solution  and  subsequent  filtration, 
the  copper  reaction  with  ferrocyanide  of  potassium  and 
acetic  acid  is  obtained,  then  abnormal  amounts  of  invert 
sugar  are  not  present. 

Dry  Substance.  Weigh  20  to  25  grams  of  the  pulp, 
well  mixed,  into  a  flat  dish  having  a  diameter  of  about 


CONTROL  IN  BEET-SUGAR  MANUFACTURE      191 

three  inches.  Spread  well  over  the  dish  by  means  of  a 
glass  rod  which  has  also  been  weighed  in  with  the  pulp. 
Dry  for  2  hours  at  70°  C.  Then  again  mix  thoroughly, 
spread  well  over  the  dish  and  dry  in  vacuum  at  105°-110°  C. 
for  approximately  8  hours,  to  constant  weight. 

EXHAUSTED  COSETTES.  Polarization.  60  grams  of  the 
pulp  are  weighed  out,  placed  into  a  metallic  beaker,  digested 
with  177  c.c.  basic  lead  acetate  solution,  as  above  directed 
for  beet  cosettes.  Take  the  polarization  reading  in  a  200 
m.m.  tube  and  read  the  percentage  direct. 

Dry  Substance.  This  determination  is  effected  as 
described  above — the  preliminary  drying  at  70°  C.  is  how- 
ever omitted. 

DRY  COSETTES.  Polarization.  Grind  the  dry  cosettes 
to  a  fine  powder.  After  a  preliminary  hot  aqueous  diges- 
tion take  12.6  grams  of  the  dry  powder  and  make  up,  with 
basic  lead  acetate  water  (100  c.c.  basic  lead  acetate  to  1 
liter  water)  to  200  c.c.,  filter,  polarize,  and  multiply  reading 
observed  by  4. 

Diffusion  and  Press  Juices.     Brix.     As  customary.     [In 

20 

Germany  the  use  of  the  table  —  °  C.  prepared  by  the  Im' 

perial  Normal  Standards  Commission  is  prescribed.] 

Polarization.  Weigh  out  26.0  grams  into  a  100  c.c. 
flask,  clarify  with  basic  lead  acetate,  make  up  to  100  c.c. 
filter  and  polarize.  Or, 

Place  100  c.c.  of  the  juice  into  a  100-110  c.c.  flask,  add 
10  c.c.  basic  lead  acetate  solution,  shake  well,  allow  to  stand 
for  10  minutes,  filter,  polarize  in  a  200  m.m.  tube  and 
determine  the  percentage  of  sucrose  from  a  Schmitz  table. 

Invert  Sugar.  10  c.c.  of  the  juice  to  be  tested  are  boiled 
with  2  c.c.  Fehling's  solution  for  2  minutes.  If  the  solution 
still  remains  blue  the  juice  contains  less  than  0.1%  invert 
sugar. 

If  however  the  Fehling's  solution  is  completely  used  up, 
then  for  every  10  c.c.  juice,  2,  3,  4  etc.,  c.c.  Fehling's  solu- 


192  SUGAR  ANALYSIS 

tion  are  tried,  in  each  instance  boiling  for  2  minutes,  until  the 
point  is  reached  where  copper  is  still  present  in  the  nitrate. 

1  c.c.  Fehling's  solution  =  0.005  gram  invert  sugar. 

Acidity.  25  c.c.  juice  are  diluted  with  sufficient  phenol- 
phthalei'n-neutral  water  *  so  that  the  change  in  color  is 
perfectly  distinct,  and  are  then  titrated  with  1/28  normal 
sodium  hydrate  solution.  The  CaO  percentage  is  found  by 
multiplying  by  4. 

Coagulation-Value.  Place  25  c.c.  of  the  raw-juice  into 
a  graduated  cylinder  about  f  inch  in  diameter,  add  3  drops 
of  glacial  acetic  acid,  heat  for  3  minutes  in  a  water-bath 
at  80°-85°C.,  remove,  allow  to  stand  at  rest  at  room-tem- 
perature for  3  hours,  read  off  the  volume  of  the  precipitate 
in  cubic  centimeters  and  multiply  by  4. 

Diffusion-Waters.  Brix.  Free  from  air  and  determine 
as  usual  by  Brix  hydrometer  or  by  means  of  a  pycnometer. 

Polarization.  Place  100  c.c.  in  a  100-110  c.c.  flask, 
clarify  with  5-8  c.c.  basic  lead  acetate  solution,  fill  up  to 
110  c.c.,  shake  well,  allow  to  stand  for  a  few  minutes,  filter 
and  polarize. 

Invert  Sugar.     As  previously  directed. 

Acidity.  Allow  the  waters  to  settle  by  standing  for 
about  5  minutes  and  then  take  the  sample,  25  c.c.,  from  the 
upper  part  of  the  vessel  by  means  of  a  graduated  pipette. 
Add  sufficient  phenol-phthalein-water  until  the  change  in 
color  can  be  distinctly  seen  and  then  titrate  with  sodium 
hydrate  solution  of  known  strength. 

Coagulation-Value.     As  previously  directed. 


*  This  is  prepared  by  adding  to  a  larger  amount  of  freshly  boiled 
distilled  water  of  its   volume  of  a  phenol-phthale'in   solution    (1 

part  by  weight  of  phenol  phthale'in  dissolved  in  30  parts  by  weight 
of  90%  alcohol)  and  then  making  alkaline  with  sodium  hydroxide 
solution  until  a  distinct  red  coloration  ensues.  This  solution  is  to  be 
freshly  prepared  every  few  days,  but  must  be  some  hours  old  before 
use. 


CONTROL  IN  BEET-SUGAR  MANUFACTURE       193 

Thin  Juices:   non-saturated  and  saturated. 

Brix.     As  previously  directed. 

Polarization.  As  directed  under  diffusion  juices.  The 
juices  of  the  first  saturation  are  to  be  neutralized  with 
acetic  acid  and  phenolphthalem. 

Color.  Determine  the  color  of  the  solution  on  which 
the  Brix  determination  has  been  made,  by  Stammer's 
colorimeter. 

Alkalinity.  To  10  c.c.  of  the  juice  there  is  added  suf- 
ficient phenol-phthalein-neutral  water  until  the  change  in 
color  is  distinctly  perceptible. 

Thick  Juices.     Brix.     As  previously  directed. 

Polarization.  Take  26.0  grams,  neutralize  with  acetic 
acid  and  phenol  phthalein,  clarify  with  basic  lead  acetate 
make  up  to  100  c.c.,  filter  and  polarize. 

Invert  Sugar.  If  the  sample  has  an  acid  reaction  or  an 
abnormal  odor,  dilute  with  water  to  about  10°  Brix,  add 
sodium  hydroxide  solution,  shake  well  and  boil  a  portion 
of  the  mixture.  If  a  distinct  brown  coloration  ensues, 
take  12.0  grams  and  determine  in  this  the  invert  sugar 
quantitatively,  as  in  raw  sugars  (which  see) . 

Dry  Substance.  On  50  grams  of  pure  sand  (free  from 
iron)  weigh  3  grams  of  thick  juice.  Dry  in  vacuo  at  105°- 
110°  C.  to  constant  weight. 

Color.     As  directed  under  thin  juices. 

Alkalinity.  To  10  grams  of  thick  juice  add  sufficient 
phenol-phthalein-neutral  water  to  make  the  color-change 
distinct,  then  titrate. 

Press-Cakes.  Polarization.*  Weigh  out  53.0  grams  of 
cold  press-cake,  place  in  a  cold  mortar  and  grind  up  with 
177  c.c.  ammonium  nitrate  solution  containing  approx- 
imately 10%  neutral  ammonium  nitrate;  this  is  added, 
gradually,  from  a  burette.  Do  not  add  basic  lead  acetate. 
Filter.  Polarize  the  filtrate  in  a  200  m.m.  tube;  the  read- 
ing so  found  represents  the  sucrose  percentage  direct. 
*  Method  of  the  German  Sugar  Institute. 


194  SUGAR  ANALYSIS 

Alkalinity  10  c.c.  of  the  filtrate  are  titrated  with  acid 
(1  c.c.  =  0.01  gram  CaO)  using  rosolic  acid  as  indicator. 
The  number  of  c.c.  of  acid  used,  multiplied  by  0.38  represents 
the  percentage  of  CaO  in  the  press-cake. 

In  case  difficulties  arise  in  the  factory  samples  of  the 
press-cakes  from  the  second  saturation  are  to  be  extracted 
with  ether,  the  latter  is  to  be  evaporated  and  the  residue 
examined  for  fats  or  oils;  furthermore,  after  boiling  with 
bicarbonate  of  soda  the  filtrate  should  be  tested  for  oxalic 
acid.  Magnesia  may  also  have  to  be  looked  for.  This 
is  done  by  suspending  a  sample  of  the  press-cake  in  water, 
oversaturating  with  carbonic  acid  gas,  boiling  the  filtrate, 
dissolving  the  precipitate  thus  formed  in  hydrochloric  acid, 
boiling  with  calcium  carbonate  and  testing  the  filtrate 
with  clear  lime  water  for  magnesia. 

Fill  Mass.  FIRST  PRODUCTS.  Polarization.  Weigh  out 
26.0  grams  into  a  100  c.c.  flask.  Cool  to  normal  tempera- 
ture, i.e.,  20°  C.,  add  3  to  4  c.c.  basic  lead  acetate  solution, 
make  up  to  100  c.c.,  shake  well,  filter,  polarize. 

Invert  Sugar.  As  previously  directed  under  invert 
sugar. 

Ash.  Weigh  3  grams  into  a  platinum  dish  of  about 
60-80  c.c.  capacity,  carefully  moisten  with  about  2  c.c. 
concentrated  sulphuric  acid,  heat  carefully  at  first,  then 
char  and  finally  incinerate  in  a  muffle. 

Lime.  Test  qualitatively  for  lime  (CaO)  with  ammonium 
oxalate,  or,  if  occasion  arises,  quantitatively  with  soap  solu- 
tion, or  by  one  of  the  usual  gravimetric  methods. 

Color.    As  previously  directed. 

Alkalinity.  Dissolve  10  grams  in  phenol-phthalein- 
neutral  water  and  titrate  with  acid  of  known  strength. 

Water  (dry  substance).  Mix  intimately  from  2  to  3 
grams  of  the  fill  mass  with  50  grams  of  pure  sand,  free  from 
iron.  Dry  at  70°  C.  for  15  or  20  minutes.  Mix  again  most 
intimately  and  then  dry  for  from  6  to  8  hours  at  105°-110° 
C.  in  vacuo  to  constant  weight.  The  latter  point  is  assumed 


CONTROL  IN  BEET-SUGAR  MANUFACTURE       195 

to  have  been  reached  when  the  difference  between  two 
successive  weighings,  two  hours  apart,  is  less  than  0.1%. 

A^TER  PRODUCTS.  Brix  and  Polarization.  Into  a  beaker 
in  which  there  is  a  glass  rod  and  both  of  which  have  been 
tared,  weigh  about  250  grams  of  the  well  mixed  sample, 
and  under  constant  stirring  gradually  add  about  250  grams 
of  warm  water  until  all  is  dissolved.  The  solution  is  then 
cooled  and  made  up  to  exactly  500  grams  with  water.  The 
degrees  Brix  of  this  solution  are  then  determined  as  usual 
and  multiplied  by  2.  The  polarization  is  found  by  weigh- 
ing out  twice  the  normal  weight,  i.e.,  52  grams  of  the  solu- 
tion, adding  5  c.c.  of  basic  lead  acetate  solution,  making 
up  to  100  c.c.,  filtering  and  polarizing. 

Invert  sugar,  as  previously  directed. 

Ash, 

Lime, 

Color, 

Alkalinity.  5.  or  10.  grams  of  the  sample — according 
to  the  color  of  the  sample — are  dissolved  in  sufficient  phenol- 
phthalein-neutral  water  that  the  change  in  color  is  distinctly 
visible  and  then  titrated  with  acid  solution  of  known 
strength. 

Water  (dry  substance).  Weigh  2  to  3  grams  of  the 
sample  in  a  dish  containing  50  grams  of  sand,  free  from 
iron.  Moisten  with  a  few  drops  of  warm  water,  mix  well 
with  the  sand.  Dry  for  2  hours  at  70°  C.,  then,  in  vacuo, 
dry  at  105°-110°  C.  to  constant  weight.  This  will  require 
from  6  to  8  hours.  The  end-point  is  reached  when  there 
is  only  about  0.1%  difference  in  the  weight  of  the  sample 
after  a  two  hours'  interval  of  drying. 

Raw  Sugar.  First  Products  and  After  Products.  Prep- 
aration of  the  Sample.  The  containers  holding  the  samples 
must  not  be  opened  until  they  have  acquired  the  tem- 
perature of  the  laboratory.  The  samples  are  then  quickly, 
but  thoroughly  mixed  and  replaced  in  the  containers  and 
the  analysis  at  once  started. 


196  SUGAR  ANALYSIS 

Polarization.  Weigh  out  26.0  grams  of  the  sample 
and  place  into  a  100  c.c.  flask,  graduated  in  metric  (true) 
cubic  centimeters  at  20°  C.,  that  is  to  say,  these  flasks 
must  contain  99.71  grams  (±0.03  gram)  of  water  at  20°  C., 
weighed  in  air  with  brass  weights.  Basic  lead  acetate 
solution  *  is  then  carefully  added  until  an  additional  drop 
of  this  reagent  produces  no  further  precipitation. 

One  or  two  c.c.  of  alumina  cream  are  also  added.  The 
contents  of  the  flask  are  then  brought  up  to  almost  the  100 
c.c.  mark,  any  foam  or  bubbles  are  dispersed  with  a  little 
ether  vapor.  The  flask  is  next  placed  into  a  water-bath 
kept  at  20°  C.  for  about  one  half  hour.  Then  it  is  removed 
and  filled  exactly  to  the  100  c.c.  mark,  any  drops  of  water 
adhering  to  the  neck  being  carefully  removed  with  filter- 
paper.  The  contents  are  then  thoroughly  mixed  and 
filtered  through  a  dry  filter  into  a  receiving  flask  or  beaker 
which  is  kept  covered  to  guard  against  evaporation.  The 
first  few  drops,  which  as  a  rule  are  turbid,  are  rejected  and 
only  the  perfectly  clear  filtrate  is  used.  The  polarization 
is  carried  out  in  a  200  m.m.  tube  at  20°  C.  in  a  saccharimeter 
which  has  been  graduated  at  20°  C.  and  which  has  been 
kept  at  20°  C.  for  at  least  2  hours  before  the  polarization 
readings  are  taken.  Accuracy  of  the  saccharimeter  must 
be  controlled  by  use  of  standard  quartz  plates  mounted 
free  from  pressure. 

*  This  solution  is  prepared  as  follows: 

3  parts  by  weight  of  basic  lead  acetate, 
1  part  of  litharge, 
10  parts  of  water. 

The  two  salts  are  intimately  ground  together  and,  after  addition 
of  one  half  part  of  water,  are  heated  in  a  closed  vessel  on  a  water- 
bath  until  the  mixture  has  turned  white  or  a  reddish  white.  Then 
the  balance  of  the  water  is  gradually  added,  and  when  the  mass  has 
been  entirely  or  almost  entirely  dissolved  to  a  turbid  solution,  the 
latter  is  set  aside  in  a  closed  vessel  to  settle  and  is  finally  filtered. 

Basic  lead  acetate  solution  must  react  alkaline  to  litmus,  but 
must  not  redden  phenol  phthalei'n.  Its  specific  gravity  must  be 
between  1,235  and  1.240. 


CONTROL  IN  BEET-SUGAR  MANUFACTURE      197 

The  saccharimeter  must  be  illumined  by  white  light 
(petroleum,  Welsbach  or  electric  light)  and  the  light  rays 
filtered  through  a  column  1.5  cm.  long  of  a  6%  potassium 
dichromate  solution. 

Invert  Sugar.  For  the  gravimetric  determination  of 
invert  sugar  use  is  made  of  Fehling's  solution.  This 
consists  as  previously  described  of  two  solutions  kept  in 
separate  flasks  and  mixed  only  immediately  before  use. 

Solution  I.  34.639  grams  pure  recrystallized  copper 
sulphate  are  dissolved  in  water  and  the  solution  is  made 
up  to  500  c.c. 

Solution  II.  173  grams  pure  crystallized  Rochelle 
salts  are  dissolved  in  distilled  water.  To  this  solution  are 
added  100  c.c.  of  a  50%  purest  sodium  hydrate  solution 
and  the  total  volume  of  the  solution  is  brought  up  to 
500  c.c. 

To  make  an  invert  sugar  determination,  25  c.c.  of 
Solution  I  and  25  c.c.  of  Solution  II  are  mixed  in  a  flask 
or  in  a  porcelain  dish  of  about  250  c.c.  capacity.  To  this 
mixed  solution  are  added  38.4  c.c.  of  the  sugar  solution 
used  for  the  polariscopic  determination  (corresponding  to 
10  grams  of  raw  sugar)  and  about  12  c.c.  pure  distilled 
water  are  added.  The  contents  of  the  flask  are  well 
mingled  by  shaking  and  the  flask  or  porcelain  dish  is  then 
placed  on  some  wire  gauze  on  which  has  been  placed  a  piece 
of  asbestos  sheeting  having  cut  in  it  a  circular  opening 
2J  inches  in  diameter.  A  flame  is  placed  under  the^flask 
or  dish  and  its  contents  heated  to  boiling  in  about  3  minutes' 
time.  As  soon  as  active  boiling  has  commenced  the  solu- 
tion is  kept  boiling  for  2  minutes;  the  flask  or  dish  is  then 
removed  and  100  c.c.  cold  distilled  water — from  which  the 
air  has  previously  been  removed  by  boiling,  is  poured 
into  the  same.  The  solution  is  then  quickly  filtered  through 
a  layer  of  asbestos-fiber  contained  in  a  glass  tube,  the 
precipitate  of  cuprous  oxide  is  washed  thoroughly  with 
about  300  to  400  c.c.  of  hot  water  and  finally  with  alcohol 


198  SUGAR  ANALYSIS 

and  ether;  it  is  then  dried  perfectly.  The  copper  can  be 
weighed  as  cuprous  oxide,  as  cupric  oxide  into  which  it  is 
transformed  by  heating  while  passing  air  through  it,  or, 
it  can  be  reduced  to  metallic  copper  by  means  of  a  current 
of  hydrogen  gas  and  weighed  as  metallic  copper. 

The  calculation  of  the  invert  sugar  corresponding  to 
the  copper  found  is  made  by  aid  of  Herzfeld's  table. 

Water.  5.  grams  of  the  sugar  are  dried  at  110°  C.  in 
vacuo  for  from  2  to  3  hours  until  approximate  constancy  of 
weight  has  been  obtained. 

Ash.  3.  grams  of  the  sample  are  treated  with  concen- 
trated sulphuric  acid  and  ignited  in  a  muffle  as  previously 
described. 

Alkalinity.  Weigh  out  10.0  grams  of  the  raw  sugar. 
Measure  out  100  c.c.  of  the  phenol-phthalein-neutral  water 
into  a  white  porcelain  dish  and  make  the  same  as  nearly 
colorless  as  possible  by  means  of  a  solution  of  test  acid, 
which  is  prepared  by  diluting  36  c.c.  normal  sulphuric  acid 
with  water  to  a  volume  of  10  liters.  1  c.c.  of  this  test  acid 
corresponds  to  a  lime  alkalinity  of  0.0001. 

Then  add  sufficient  of  the  test  sodium  hydrate'  solution 
until  the  fluid  has  again  turned  a  faint  red.  This  test 
sodium  hydrate  solution  is  standardized  against  the  test 
acid  solution  above  referred  to  and  hence  1  c.c.  of  the  same 
also  corresponds  to  a  lime  alkalinity  of  0.0001. 

The  red  coloration  obtained  must  however  be  only 
strong  enough  that  it  will  again  completely  disappear 
on  the  addition  of  one  cubic  centimeter  of  the  test  acid 
solution,  immediately  before  the  addition  of  the  raw  sugar 
solution. 

The  10  grams  of  the  raw  sugar  are  then  at  once  dissolved 
in  this  solution.  If  the  red  coloration  of  the  water  remains 
on  dissolving  the  sugar  in  the  same,  or,  if  it  increases  in 
depth  the  sugar  is  alkaline,  if  the  color  disappears,  the 
sugar  is  acid. 

In  case  of  doubt,  one  must  determine  by  titration  with 


CONTROL  IN  BEET-SUGAR  MANUFACTURE      199 

the  test  acid  as  well  as  with  the  test  alkali  solution  in  which 
direction  the  change  of  color  occurs. 

If  the  sugars  tested  are  so  dark  that  the  use  of  100  c.c. 
of  water  of  solution  are  not  sufficient  to  produce  a  sugar 
solution  sufficiently  light  in  color  to  permit  of  the  titration, 
more  water  must  be  used,  this  however  is  permissible 
only  when  100  c.c.  will  not  suffice  for  the  purpose. 

Sugars  which  react  neutral  under  this  method  of  procedure 
are  classed  as  alkaline. 

Molasses.  Brix.  To  250  grams  of  the  sample  add 
250  grams  of  water  and  effect  perfect  solution  without 
aid  of  heat.  Determine  the  degree  Brix  of  this  solution 
and  then  correct  for  temperature. 

Polarization.     Use   26.0   grams   and   proceed   as   usual. 

Apparent  Purity.  Having  determined  the  corrected 
degree  Brix  of  the  solution  and  its  polarization  calculate 
the  purity  by  the  formula: 

,  T.     >jL       Polarization  X 100 
Apparent  Purity  =     DegreesBrix 

Invert  Sugar.     As  previously  described. 

Water.  Weigh  out  10  grams  of  the  sample,  add  10  grams 
of  absolute  alcohol.  Mix  intimately  with  50  grams  of 
pure  sand.  Evaporate  to  dryness  on  a  water-bath,  add 
10  grams  more  of  absolute  alcohol  and  repeat  evaporation 
to  dryness  on  a  water-bath.  Then  place  the  sample  in  an 
air-bath  or  in  a  vacuum  stove  and  dry  for  2J  hours  at  100° 
C.  Cool  in  a  desiccator  and  weigh.  Repeat  this  heating 
for  an  additional  hour  at  100°  C.  and  reweigh.  Carry 
to  constant  weight. 

Ash.  Take  10  grams  of  the  sample  moisten  with  20 
drops  of  dilute  sulphuric  acid  (1:1)  pour  a  little  ether  over 
the  contents  of  the  dish  and  ignite  cautiously.  When 
mass  is  fully  carbonized,  place  in  a  muffle  and  incinerate. 
Deduct  10%  from  the  weight  found. 


200  SUGAB  ANALYSIS 

Cattle  Food.  Water.  Dry  5.0  grams  at  100°  C.  for 
12  hours.  Cool,  weigh.  Continue  drying  and  reweighing 
at  intervals  of  one  hour  until  practically  constant  weight 
has  been  attained. 

Ash.  Use  2.0  grams,  moisten  with  sulphuric  acid, 
heat  carefully,  then  incinerate,  cool  and  weigh. 

Crude  Protein.  Make  a  Kjeldahl  determination  as 
directed  in  Chapter  VII.  The  percentage  found  multiplied 
by  the  factor  6.25  represents  the  crude  protein. 

Crude  Fiber.  Use  2.0  grams  for  the  determination. 
Extract  with  ether.  Place  the  residue  in  a  500  c.c.  flask 
and  add  200  c.c.  boiling  sulphuric  acid  having  a  strength 
of  1.25  %.  Boil  for  one  half  hour  having  the  flask  con- 
nected with  a  reflux  condenser.  Filter,  wash  residue  with 
boiling  water  until  free  from  acid. 

Wash  the  material  back  into  original  flask  with  200 
c.c.  boiling  solution  of  sodium  hydrate  having  a  strength 
of  1.25%.  Again  boil  for  one  half  hour.  Place  residue 
in  a  tared  Gooch  crucible  and  wash  to  neutral  reaction 
with  boiling  water.  Dry  residue  at  110°  C.  Weigh, 
ignite  and  burn  completely  to  ash.  Then  reweigh.  The 
loss  of  weight  found  represents  the  crude  fiber. 

Ether  Extract.  Extract  about  3.0  grams  with  anhydrous 
ether  free  from  alcohol  in  a  Soxhlet  tube  on  a  steam  bath 
or  on  an  electric  plate.  Run  this  extraction  for  16  hours, 
remove  the  ether  by  evaporation  and  dry  extract  to  con- 
stant weight  at  about  100°  C.  The  residue,  expressed  in 
percentage  on  the  original  material  used,  is  recorded  as 
the  ether-extract. 

Sucrose.  Invert  and  determine  as  invert  sugar  by 
Fehling's  solution,  as  previously  directed. 

Invert  Sugar.  Determine  by  Fehling's  solution,  as  pre- 
viously directed. 

Waters:  Condenser,  Waste  and  Boiler-Feed  Waters. 
a-naphthol  Test.  Place  5  c.c.  of  the  water  to  be  examined 
into  a  test-tube,  add  2  or  3  drops  of  a  10%  solution  of 


CONTKOL  IN  BEET-SUGAR  MANUFACTURE      201 

a-naphthol.  Then  pour  a  few  cubic  centimeters  of  con- 
centrated sulphuric  acid — free  from  any  trace  of  nitric 
acid — carefully  along  the  sides  of  the  tube  so  that  it  will 
settle  at  the  bottom.  If  even  very  small  amounts  of  sucrose 
are  present  a  violet  zone  will  appear  at  the  line  of  contact 
of  the  two  liquids.  This  test  is  a  qualitative  one,  although 
some  indication  of  the  amount  of  sucrose  present  can  be 
had  from  the  intensity  of  the  coloration.  If  any  appreciable 
amount  of  sucrose  is  shown,  a  quantitative  determination 
by  the  polariscope  must  be  made. 

Polarization.  Evaporate  about  4  liters  of  the  sample 
in  a  dish,  wash  the  residue  into  a  200  c.c.  flask  and  add  a 
few  drops  of  phenol-phthalein  solution.  Decolorize  with 
acetic  acid,  then  clarify  with  basic  lead  acetate  solution. 
When  perfectly  cold,  shake  well,  filter  and  polarize  in  a 
400  m.m.  tube.  Calculate  the  result  on  the  original  amount 
of  water  taken. 


CHAPTER  XI 
ANALYTICAL  CONTROL  IN  REFINERIES 

Determinations  Required.  The  following  determina- 
tions are  necessary  for  the  current  control  of  a  sugar  refinery; 
the  number  of  samples  taken  for  analysis  are  of  course 
determined  by  local  conditions. 


Sample. 

Determinations  to  be 
Made. 

Number  of  Determinations 
in  24  Hours. 

{Polarization        j 

Raw  sugar  purchased 

Invert  sugar 
Water             1 

Every  lot 

Ash 

{Polarization        1 

Raw  sugar  stacked 

Invert  sugar 
Water 

Every  lot 

Ash 

(       Polarization        "1 

Raw  sugar  melted 

J       Invert  sugar 
Water 

Every  lot 

I            Ash 

Washed  sugar 

f       Polarization        "1 
\       Invert  sugar       / 

12 

Remelt  sugar 

f       Polarization        "I 
\       Invert  sugar       J 

12 

{Polarization        "j 

Car-sugar 

Invert  sugar 
Water 

2 

Ash              J 

Refined  sugar 

Polarization 

Every  lot 

/              Brix  .            \ 

Fill  mass 

\       Polarization       / 

Every  strike 

202 


ANALYTICAL  CONTROL  IN  REFINERIES         203 


Sample. 

Determinations  to  be 
Made. 

Number  of  Determinations 
in  24  Hours. 

Pan  Specials 
Fill  mass 

Brix 

Polarization 

} 

Whenever  taken 

f              Brix 

} 

Blow-ups 

\       Polarization 

} 

12 

Liquors, 
First,  second,  third, 
fourth 

Brix 

|        Polarization 
Invert  sugar 

\ 

Hourly  samples  to  be 
taken 
12  composite  samples 
of  each  grade 

Washed  sugar  liquors 

Brix 

Polarization 
Invert  sugar 

I 

Hourly  samples  to  be 
taken.       12       com- 
posite    samples     of 
each  grade 

Brix 

} 

Hourly  samples  to  be 

Char-sweet  water 

•1        Polarization 

taken.     8  composite 

[       Invert  sugar 

1 

samples. 

Concentrated  sweet- 
water 

(              Brix 
\        Polarization 
I       Invert  sugar 

] 

Hourly  samples  to  be 
taken.     8  composite 
samples. 

(              Brix 

} 

Bag  filter  washings 

J        Polarization 

6 

{      Invert  sugar 

f 

f             Brix 

Pan  syrups 

j        Polarization 

> 

24 

I            Purity 

[              Brix 

Cyclone  syrups 

|        Polarization 

2 

I           Purity 

f             Brix 

Polarization 

Barrel  syrups 

Purity 
Clerget 

Every  lot 

Invert  sugar 

Ash 

(Brix 

Polarization 

Molasses 

Purity 
Clerget 

Every  lot 

Invert  sugar 

Ash 

Press-cakes 

f       Polarization 
\            Water 

• 

3  composite  samples 

Press-water 
On: 

f             Brix 
•{        Polarization 
I  •          Purity 

1 

Hourly  samples  to  be 
taken.     4  composite 
samples 

204 


SUGAE  ANALYSIS 


Sample. 

Determinations  to  be 
Made. 

Number  of  Determinations 
in  24  Hours. 

Press-water 

f             Brix              | 

Hourly  samples  to  be 

Off: 

\        Polarization 

taken.     4  composite 

I            Purity 

samples 

I              Brix  .            1 

Press-cloths  water 

\        Polarization        r 

3 

1            Purity            J 

Bag  filter  water 

Brix 

2 

Bags        1 

j       Polarization 

2. 

Sheathes  / 

I            Purity 

Condenser  water 

a  naphthol        \ 
Polarization  when  I 
indicated          J 

Continuous  automatic 
sample  to  be  taken.  8 

Waste  water 

a-naphthol         ) 
Polarization  when  r 
indicated          J 

Continuous  automatic 
sample  to  be  taken.  8 

f 

Alkalinity         } 

Boiler-feed  water 

a-naphthol 
Polarization  when  | 

Continuous  automatic 
sample  to  be  taken.  8 

I 

indicated      J 

Phosphoric    acid     or 
phosphoric        acid  j 

(hydrochloric 
or 

3 

paste 

sulphuric  acid  J 

Bone-black    from   kilns 

Caustic  soda  test 

Every  kiln.     6 

•f 

Density           "j 

Hydrochloric  acid        \ 

Iron 

Every  lot 

( 

Arsenic            J 

The  analytical  determinations  to  be  made  as  above 
indicated  have  been  so  fully  considered  in  previous  chapters 
that  reference  shall  here  be  made  only  to  such  determina- 
tions as  have  not  before  received  special  attention. 

Density  Determination  of  Fill  Mass.  Apparent  Density. 
Weigh  out  250  grams  of  the  fill  mass,  add  250  grams  of  water, 
carefully  dissolve  all  crystals  and  mix  the  sample  thoroughly. 
Determine  the  degree  Brix  of  this  solution,  correct  for 
temperature  and  multiply  the  corrected  value  by  2. 

Noel    Deerr  *    determines    the    apparent    and  the  real 
specific  gravity  of  fill  masses  in  the  following  way. 
*  Cane  Sugar,  1911,  p.  483. 


ANALYTICAL  CONTROL  IN  REFINERIES         205 

The  fill  mass  to  be  tested  is  allowed  to  flow  into  a  large 
wide-mouthed  vessel  of  metal  or  glass  the  mouth  of  which 
slopes  inward  and  which  is  provided  with  an  accurately 
fitting  stopper.  This  vessel  is  filled  to  about  seven-eighths 
of  its  capacity.  Vessel  and  contents  are  then  cooled  to 
the  temperature  at  which  the  factory  measurements  of  the 
fill  mass  are  taken  and  the  weight  of  the  fill  mass  in  the 
vessel  ascertained. 

If  the  apparent  specific  gravity  of  the  fill  mass  is  to  be 
determined  the  vessel  is  next  completely  filled  with  water 
and  the  perforated  stopper  is  inserted;  any  excess  of 
water  passes  through  the  hole  in  the  stopper  and  is  removed. 

Real  Density.  If  the  real  specific  gravity  is  desired, 
oil  or  any  other  fluid  indifferent  to  sugar  is  used  in  place  of 
the  water,  the  specific  gravity  of  such  reagent  has  of  course 
been  previously  determined. 

Example.  Grama. 

Vessel,  stopper,  water  2163.40 

Vessel,  stopper — empty  416.35 

Water  1747.05 


Vessel,  stopper,  fill  mass  2645.95 

Vessel,  stopper — empty  416.35 

Fill  mass  2229.60 


Vessel,  stopper,  water,  fill  mass  2875 . 95 

Vessel,  stopper,  fill  mass  2645.95 

Water  above  fill  mass  230 . 00 


Water  1747.05 

Water  above  fill  mass  230 . 00 


Water  in  space  occupied  by  fill  mass  1517.05 

Apparent  specific  gravity  of  fill  mass  =  ..       '     =  1.469. 

1517. U5 


206  SUGAR  ANALYSIS 

Whenever  the  real  specific  gravity  is  sought  and  an  oil, 
for  instance,  is  used,  the  calculation  is  effected  as  follows: 
Example. 

Weight  of  fill  mass 


Weight  of  an  equal  volume  of  oil 


=  x. 


Specific  gravity  of  the  oil  referred  to  water  =  0.862 

True  sp.gr.  of  fill  mass  =  0.862  x. 

Composition  of  Fill  Mass.  A  knowledge  of  the  com- 
position of  the  fill  mass  is  a  factor  of  prime  importance  in  a 
sugar  house. 

The  direct  determination  of  the  crystal  content  and  of 
the  syrup  in  a  fill  mass  is  analytically  carried  out  by  Sidersky  * 
as  follows: 

Make  an  ash  determination  of  the  fill  mass  as  usual  by 
the  sulphuric  acid  method.  Then  place  some  of  the  fill 
mass — if  need  be,  after  having  slightly  warmed  it,  upon  a 
fine  wire  gauze  and  allow  the  syrup  to  drain  from  it.  On 
this  syrup  make  another  ash  determination,  this,  of  course, 
represents  the  ash  of  the  syrup  originally  adhering  to  the 
sucrose-crystals  in  the  fill  mass.  As  sucrose  crystals  are 
free  from  mineral  matter  all  of  the  ash  must  be  present 
in  the  syrup. 

The  amount  of  the  adherent  syrup  is  then  calculated 
as  follows: 

Example.     Ash  found  in  fill  mass  =  3. 14% 
"       "       syrup     =9.24%. 
x  =  amount  of  syrup 
x  :  100::  3.14  :  9.24 
x  =  33.98%    syrup, 
and  100.00-33.98  =  66.02%  sucrose  crystals  in  fill  mass. 

A  number  of  methods  have  been  devised  for  calculating 
the  amount  of  sucrose  crystals  and  of  syrup  constituting  a 

*  Neue  Zeitschrift  fur  Rubenz acker-Industrie,  Vol.  28,  1892,  p.  161. 


ANALYTICAL  CONTROL  IN  REFINERIES         207 

fill  mass.*     One    of    these  methods  is  illustrated  by  the 

following  example: 

A  fill  mass  has  the  composition: 

Polarization  88  .  0 

Water  3.5 


Hence  its  Coefficient  of  Purity  =  =  9  1.2.    The 


sugar  which  is  obtained  from  this  fill  mass  has  the  com- 

position : 

Polarization  95  .  3 

Water  2.0 

n    «     CT>    •*       95.3X100     ___ 
Coeff.  of  Purity  =  ^-^-  =  97.2 

The  resultant  syrup  has  the  composition: 

Polarization  66  .  0 

Water  12.0 

66X100 


Represent  the  coefficient  of  purity  of  the 

Fill  mass  by  s 

Sugar         "  r 

Syrup         "  t 

and,  the  amount  of  sugar  by  x,  the  amount  of  syrup  by  y. 
Then: 


s-t 


r—s 


*For  a  detailed  discussion  of  similar  problems,  see:    Mittelstaedt- 
Bourbakis,  Technical  Calculations  for  Sugar  Works,  1910. 


208  SUGAE  ANALYSIS 

Substituting  in  these  formulae  the  values  of  the  present 
example, 

91.2-75.0 


97.2-75.0 


72.97  dry  sucrose 


97^2-  75.0  =27-03 


100.00  dry  fill  mass. 
Taking  the  water  present  into  account, 

100X72.97     7, 

98  Q       =74.  46  sucrose, 

100X27.03 

88.0       =30.  71  syrup. 

105.17 

105.17  :  74.66::  100  :  x  =  70.8%  sucrose 
105.17  :  30.71::  100  :  y  =  29.2%  syrup 

100.0 

By  analyzing  the  fill  mass  of  each  strike  it  is  easy  to 
keep  track  as  to  whether  the-  boiling  in  the  pans  and  the 
work  at  the  centrifugals  are  being  properly  done.  For  this 
purpose  a  sample  of  the  fill  mass  is  secured,  a  part  of  it 
spun  in  a  laboratory  centrifugal  and  the  purity  of  the  re- 
sultant syrup  determined. 

Another  portion  of  the  fill  mass  is  dissolved  in  water, 
the  solution  made  up  to  about  15°  Brix  and  its  apparent 
purity  ascertained. 

Let  x  =  per  cent  of  sugar  obtainable, 
a  =  purity  of  fill  mass, 
b  =  purity  of  syrup  resulting 

(a  —  b)  factor 
then  x  =  -  -  -  - 


ANALYTICAL  CONTROL  IN  REFINERIES         209 

The  table  of  factors,  (Table  XVIII)  given  by  Irving 
H.  Morse,*  is  especially  adapted  for  use  in  refinery  work. 

To  find  a  factor  in  this  table  consult  the  column  headed 
by  the  polarization  of  the  sugar  obtained.  The  factor 
sought  will  be  found  in  this  column  at  the  point  of  intersec- 
tion of  a  line  drawn  straight  across  from  the  "  Purity  of 
Molasses  "  column. 

Thus,  if  the  polarization  =  99.0  and  the  purity  of  molasses 
=  91.0  the  factor  sought  =  12.35. 

Yield  or  Rendement.  The  yield  or  rendement  of  a  sugar 
is  supposed  to  indicate  how  much  crystallized  sugar  can  be 
obtained  from  a  given  raw  sugar.  In  other  words  it  is 
supposed  to  represent  the  output  in  white,  marketable 
product  obtainable  from  a  raw  sugar — its  refining  value. 

Different  methods  of  calculating  the  yield  have  been 
and  are  in  vogue  in  different  countries.  At  best,  all 
yield  calculations  are  unreliable,  and  yet,  as  they  afford  a 
certain  approximation  to  actual  working  possibilities,  they 
continue  to  have  a  certain  importance  in  the  industry. 

The  method  of  yield  calculation  perhaps  most  commonly 
used  is  known  as  the  ash-coefficient  method;  the  ash  is 
multiplied  by  5  and  the  product  subtracted  from  the  polar- 
ization. This  method  is  due  to  Monnier,  1863,  and  is 
based  on  certain  relations  which  he  observed  between  the 
ash  of  certain  raw  sugars  and  the  amounts  of  sucrose  therein 
which  could  not  be  brought  to  crystallization.  From  his 
observations  he  inferred  that  one  part  of  the  mineral  impur- 
ities present  (the  ash)  prevented  five  parts  of  sucrose  from 
crystallizing  and  hence  deducted  five  times  the  ash  from 
the  polarization  to  arrive  at  the  refining  value  of  the  sugars. 

As  stated,  this  method  of  calculating  the  yield  is  per- 
haps the  one  most  generally  used.  Frequently  however 
the  invert  sugar  contained  in  a  raw  sugar  is  also  taken  into 
account.  Thus,  in  France,  the  formula,  polarization  less 
four  times  the  ash  plus  twice  the  invert  sugar,  is  much  used; 
*  Calculations  used  in  Cane-sugar  factories,  1904. 


210  SUGAR  ANALYSIS 

\ 

from  the  figure  thus  obtained,  an  additional  1.5%  is  sub- 
tracted to  allow  for  loss  in  refining  operations. 

In  Germany,  for  a  time,  the  total  non-sugars  were 
multiplied  by  2.25  and  this  amount  was  deducted  from  the 
polarization.  Of  late  however  this  method  has  been  aban- 
doned and  the  Monnier  formula  is  now  again  used. 

The  yield  in  crystallizable  sugar  can  be  analytically 
determined  by  the  Payen-Scheibler  method. 

This  process  is  based  on  the  treatment  of  the  raw  sugar, 
the  rendement  of  which  is  to  be  ascertained,  by  solutions 
that  will  wash  out  the  molasses-forming  impurities,  and 
leave  behind  the  pure  crystallizable  sugar. 

Five  solutions  are  required: 

No.  1  is  a  mixture  in  equal  parts,  by  volume,  of  absolute 
alcohol  and  ether. 

No.  2  is  absolute  alcohol. 

No.  3  is  alcohol  of  96  per  cent  Tralles.* 

No.  4  is  alcohol  of  92  per  cent  Tralles. 

No.  5  is  alcohol  of  85  per  cent  to  86  per  cent  Tralles, 
to  which  50  c.c.  of  acetic  acid  per  liter  have  been 
added. 

Solutions  Nos.  3,  4,  and  5  are  all  saturated  with  pure 
sugar,  and,  in  order  that  they  should  remain  saturated 
with  sugar  at  all  temperatures,  they  are  kept  in  flasks 
which  are  half  filled  with  best  granulated  sugar,  previously 
washed  with  absolute  alcohol. 

These  flasks  are  provided  with  a  siphon  arrangement; 
the  air  enters  through  chloride-of-calcium  tubes,  so  as  to 
be  thoroughly  dried;  the  solution  is  discharged  through 
tubes  filled  with  pure  and  dry  sugar.  Plugs  of  felt  placed 
at  the  ends  of  these  tubes  prevent  the  carrying  over  of 
any  sugar  particles. 

The  washing  operation  is  carried  out  as  follows:     The 

*  The  alcoholometer  of  Tralles  gives  the  percentage  volume  for  the 
temperature  of  60°  F.  =  15f°  C.  Watt's  Dictionary  of  Chemistry, 
Vol.  I,  p.  84. 


ANALYTICAL  CONTROL  IN  REFINERIES         211 

accurately  weighed  sample,  usually  13.024  grams,  is  placed 
into  a  50  c.c.  flask  which  has  previously  been  dried. 

A  cork  or  a  rubber  stopper,  through  which  two  glass 
tubes  are  made  to  pass,  serves  to  close  the  flask.  One 
of  these  tubes  reaches  down  almost  to  the  bottom  of  the 
flask;  it  is  provided  with  a  felt-plug  at  its  mouth;  this 
serves  as  strainer.  The  shorter  tube  only  reaches  to  just 
below  the  cork  or  stopper.  The  longer  tube  is  connected, 
by  means  of  a  rubber  tube  with  a  large  receiving  bottle, 
from  which  the  air  is  to  a  great  extent  exhausted  by  an 
aspirator  or  a  vacuum  pump.  The  rubber  tube  is  pro- 
vided with  a  pinch-cock,  so  that  connection  can  be  made 
or  broken  at  will,  between  the  receiving  bottle  and  the 
small  flask  which  holds  the  sample. 

The  apparatus  being  thus  arranged,  about  30  c.c.  of 
solution  No.  1  is  allowed  to  flow  into  the  flask  containing 
the  sugar.  This  solution  is  permitted  to  remain  quietly 
in  contact  with  the  sample  for  from  fifteen  to  twenty 
minutes,  and  is  then  drawn  over  into  the  receiving  bottle. 
When  it  has  all  been  drained  over,  30  c.c.  of  solution  No. 
2  are  introduced.  After  a  contact  of  two  minutes  this 
solution  is  drawn  off,  and  followed  successively  by  about 
the  same  amounts  of  the  other  three  solutions,  in  the  order 
of  their  numbering. 

The  last  of  these,  solution  No.  5,  is  really  the  active 
reagent,  the  others  principally  serving  to  displace  the 
moisture  contained  in  the  sugar. 

This  solution  is  allowed  to  remain  on  the  sample  for 
half  an  hour,  being  frequently  and  well  shaken  in  the 
mean  time  to  insure  intimate  contact. 

It  is  then  drawn  off,  and  replaced  by  a  fresh  supply 
of  the  same  solution.  This  in  turn  is  drawn  off,  and  the 
treatment  is  repeated  with  fresh  amounts  of  solution  No.  5, 
until  the  solution  standing  above  the  sugar,  remains  per- 
fectly colorless.  The  time  of  contact  is  thirty  minutes  for 
each  treatment. 


212  SUGAR  ANALYSIS 

The  last  traces  of  solution  No.  5  are  then  removed 
by  successive  addition  of  solutions  Nos.  4,  3,  and  2,  in  the 
order  named.  These  are  added  and  drawn  off  at  intervals 
of  two  minutes  each.  The  last  traces  of  alcohol  are  re- 
moved by  drying  on  a  water-bath,  a  current  of  dry  air  being 
continuously  drawn  through  the  flask  in  the  mean  time. 
When  the  sample  is  perfectly  dry,  the  cork  with  its  inserted 
tubes  is  carefully  withdrawn,  and  any  sugar  clinging  to  the 
long  tube  or  its  felt  plug,  is  carefully  washed  into  the  flask. 
The  solution  is  then  made  up  to  50  c.c.  and  polarized.  The 
reading  on  the  polariscope  represents  in  percentage  the 
yield  in  crystallizable  sugar. 

Other  methods  of  determining  the  crystallizable  sugar 
or,  as  it  may  be  termed,  the  crystal  content  of  sugars, 
obviating  some  of  the  difficulties  inherent  in  the  Payen- 
Scheibler  method,  have  been  devised  by  Koydl  and  by 
Herzfeld  and  Zimmermann.  In  the  latter  method  the 
washing  liquid  employed  is  a  saturated  aqueous  solution 
of  sucrose;  this  method  is  to  be  recommended  on  account 
of  its  ease  of  manipulation. 

If  the  crystal  content  of  a  raw  sugar  is  known,  it  is  a 
simple  matter  to  determine  the  composition  and  purity  of 
the  molasses  in  the  raw  sugar  by  deducting  the  sucrose  of 
the  crystals  from  that  of  the  raw  sugar  and  then  figuring 
the  remainder  as  due  to  molasses.* 

Hints   on   Reporting   Sugar   Analyses.    In  commercial 
analyses  it  is  customary  to  report  only- 
Polarization, 
Invert  sugar, 
Water, 
Ash, 
Non-ascertained, 

*  For  a  full  account  of  these  methods  see  C.  A.  Browne,  Hand- 
book of  Sugar  Analysis,  1912,  p.  501  et  seq. 


ANALYTICAL  CONTROL  IN  REFINERIES         213 

the  "  non-ascertained  "  being  the  balance  required  to  make 
the  analysis  figure  up  to  100. 

When  beet-sugars  are  examined,  and  a  raffinose 
determination  has  been  made,  this  substance,  of  course, 
makes  another  item  in  the  report,  which  would  then 
embrace : 


Polarization, 

Sucrose, 

Raffinose, 

Invert  sugar, 

Water, 

Ash, 

Non-ascertained. 


The  polarization  in  the  first  form  of  analysis  given 
above,  may  either  correspond  to,  be  greater,  or  smaller 
than  the  amount  of  sucrose  really  present,  for  the  presence 
of  other  optically  active  bodies  influences  the  polariscope 
reading  to  a  marked  degree. 

Invert  sugar  turns  the  plane  of  polarized  light  to  the 
left.  At  17.5°  C.  one  part  of  invert  sugar  neutralizes  the 
optical  effect  of  about  0.34  part  of  sucrose.  In  order, 
therefore,  to  obtain  the  sucrose  corrected  for  this  disturbing 
influence,  the  amount  of  invert  sugar  found  is  multiplied 
by  0.34,  and  the  result  is  added  to  the  direct  polarization. 
This  sum  is  then  regarded  as  approximately  representing 
the  sucrose. 

Frequently  a  polarization  after  inversion  is  made,  and 
compared  with  the  direct  polarization. 

If  there  are  no  other  optically  active  bodies  present 
in  the  sample  besides  the  sucrose,  the  result  of  the  polari- 
zations before  and  after  inversion  will  be  identical,  or  at 
least  agree  very  closely.  If  the  polarization  after  inver- 
sion is  higher  than  the  direct  polarization,  the  presence 


214  SUGAR  ANALYSIS 

of  levo-rotatory  bodies  is  indicated;  if  it  is  lower,  dextro- 
rotatory substances  are  present. 

Investigation  has,  however,  shown  that  this  method 
of  inversion  and  subsequent  polarization  (Clerget's  test) 
is  not  always  applicable  to  sugars  rich  in  reducing  sugars 
(so-called  invert  sugar),  because  the  inverting  acid  (hydro- 
chloric acid)  changes  the  levo-rotation  of  the  invert  sugar, 
and  because  the  reducing  sugar  sometimes  consists  of  a 
mixture  of  levo-  and  of  dextro-rotatory  substances  in  vary- 
ing proportions. 

In  dealing  with  samples  of  such  description,  as,  for 
instance,  with  low  sugars  and  molasses,  sugar-cane  prod- 
ucts, etc.,  an  exhaustive  analysis  is  desirable,  in  order 
to  gain  all  information  possible  with  regard  to  the  nature 
of  the  sample. 

Such  an  analysis  should  record — 

Reaction  (acid,  alkaline,  or  neutral), 

Total  sucrose, 

Direct  polarization, 

Polarization  after  inversion, 

Total  reducing  sugars, 

Water, 

Ash. 

The  correct  interpretation  of  an  analysis  of  this  descrip- 
tion is  not  always  an  easy  matter. 

If  the  polarization  after  inversion  agrees  with  the 
direct  polarization  plus  0.34  times  the  total  reducing  sugar, 
this  value  may  be  regarded  as  the  amount  of  sucrose  present. 
As,  however,  all  results  obtained  by  the  Clerget  method 
on  sugars  rich  in  invert  sugar  are  open  to  some  doubt, 
it  will  be  better,  even  in  case  the  direct  polarization  plus 
0.34  times  the  total  reducing  sugar  is  equal  to  the  polariza- 
tion after  inversion,  to  resort  to  gravimetric  determinations 
for  verification. 


ANALYTICAL  CONTROL  IN  REFINERIES         215 

In  case  of  non-agreement  of  the  direct  polarization 
plus  0.34  times  the  total  reducing  sugar,  and  the  Clerget 
test,  gravimetric  analysis  must  of  course  be  employed. 

Determine  the  total  sucrose  after  inversion,  by  its 
reducing  action  on  copper  solution,  and  determine,  also 
by  gravimetric  analysis,  the  total  reducing  sugar.  Calculate 
the  latter  over  to  its  equivalent  of  sucrose  by  subtracting 
one  twentieth  of  the  amount  found;  deduct  this  result 
from  the  total  sucrose,  and  report  the  remainder  as 
sucrose. 

Example. 

Polarization  before  inversion,    .      .      .  52.70 

Polarization  after  inversion,      .      .      .  63 . 12 

Total  reducing  sugar,        22 . 89 

Total  sucrose  (gravimetric  det.),    .      .  79.20 
22.89  Total  sucrose,     79.20 
1.14  Less    .     .      .     21.75 

21.75      Sucrose     =     57.45 


Sucrose  Loss.  By  this  term  there  is  understood  the 
difference  between  the  amount  of  sucrose  .vhich  enters 
into  the  process  of  manufacture  and  the  amount  of  sucrose 
which  is  turned  out  by  the  process  of  manufacture  in  any 
and  every  form. 

Presupposing  correct  weighing  of  all  raw  material 
received  for  refining  purposes  and  of  all  products  turned 
out;  furthermore  presupposing  correct  analytical  work 
and  correct  clerical  work  in  the  making  up  of  the  technical 
statements,  the  sucrose  losses  sustained  must  be  due  to 
chemical  causes,  to  mechanical  causes,  or  to  both. 

When  studying  sucrose  losses  through  chemical  and 
mechanical  causes,  the  following  points  should  be  especially 
kept  in  view. 


216  SUGAR  ANALYSIS 

Chemical  Losses. 

1.  Formation   of  invert  sugar  through  acidity,  bac- 

terial influence,  overheating. 

2.  Formation  of  gums  through  bacterial  influence. 

3.  Destruction  of  sucrose  through  caramelization,  in 

vacuum  pans  through  overheating. 

Mechanical  Losses. 

4.  In  press  cake. 

5.  In  washing  plant  of  bags,  filter-cloths,  etc. 

6.  By  entrainment. 

7.  Through  leaks  and  overflows. 

8.  By  theft. 


CHAPTER    XII 

RESUME  OF  THE  WORK  OF  THE  INTERNATIONAL  COM- 
MISSION FOR  UNIFORM  METHODS  OF  SUGAR  ANALYSIS 

ALEXANDER    HERZFELD,    Chairman,    F.    C.    WIECHMANN,    American 

Secretary. 

FIRST   SESSION:  Hamburg,    Germany,  June   12th,  1897 . 

(1.)  Kinds  of  quartz  plates  to  be  selected. 

At  the  start  only  quartz  plates  of  high  polarizing  value 
shall  be  tested,  later  however,  such  also  as  will  cover  the 
entire  scale-range  of  saccharimeters. 

(2.)  Method  of  examination  of  quartz  plates. 

Their  examination  is  to  be  conducted  in  the  same  manner 
as-  has  been  done  heretofore  by  the  Commission  of  Trades- 
cheijpists,  under  guidance  of  the  Society  of  the  Beet  Sugar 
Industry  of  the  German  Empire,  with  the  participation  of 
the  Imperial  Normal  Testing  Bureau  and  the  Physical- 
Technical-Reichsanstalt. 

(3.)  Temperature  to  be  adopted  as  the  normal-temperature 
for  polarization. 

For  the  examination  of  quartz  plates  20°  Centigrade 
is  to  be  chosen  as  the  normal  temperature,  and  the  metric 
liter  is  to  be  adopted.  The  normal  weight  to  be  adopted 
is  hence  to  be  26.00  grams,  where  26.048  grams  is  the  normal 
weight  valid  for  Mohr's  liter  at  the  temperature  17  J° 
Centigrade. 

(4.)  Additional  methods  and  means  suggested  in  order  to 
decrease  differences  in  polarization  work. 

217 


218  SUGAR  ANALYSIS 

In  consideration  of  the  well-known  difficulties  in  sampling 
bagged  sugar,  sampling  each  bag  does  not  offer  sufficient 
advantages  to  justify  a  departure,  in  the  interests  of  trade, 
from  the  customary  method  of  sampling  20  bags  in  every 
100  bags. 

(5.)  Desirability  of  an  endeavor  to  introduce  uniformity 
of  analytical  methods  for  beet-sugar  work  in  all  countries 
concerned. 

Such  an  endeavor  shall  be  made.  For  the  computation 
of  sugars,  analyses  shall  be  admissible  only  of  such  chemists 
as  shall  have  pledged  themselves  to  execute  the  analysis 
of  sugar  in  accordance  with  the  methods  prescribed  by  the 
International  Commission. 

(6.)  The  determination  of  invert  sugar. 

The  determination  of  invert  sugar  is  to  be  made  only 
in  solutions  which  have  been  clarified  with  lead  solution 
and  from  which  the  lead  has  then  been  removed.  If  volu- 
metric determinations  are  made,  the  amount  of  reduction 
due  to  the  chemically  pure  sucrose  must  be  deducted. 

SECOND  SESSION:  Vienna,  Austria,  July  31st,  1898. 

(1.)  Results  of  the  International  examination  of  quartz 
plates. 

In  general,  such  examinations  proved  satisfactory. 
Certain  discrepancies  were  undoubtedly  due  to  the  fact 
that  the  examinations  had  not  always  been  made  at  20°  C., 
as  prescribed. 

Reference  was  made  to  the  observations  of  Herzfeld, 
Wiechmann,  and  Wiley,  that  pressures,  due  to  varying 
temperatures  affecting  their  mountings,  exercise  an  influence 
on  the  rotation  values  of  fixedly  mounted  quartz  plates  and 
quartz-wedges.  Whereas  the  quartz  plates  heretofore  used 
— owing  to  the  fact  of  their  being  firmly  held  in  their  mount- 
ings— are  apt  to  be  strained  when  their  temperature  is 
raised,  and  whereas  such  strains  cause  irregularities  in  the 
polarizing  values  of  these  plates,  it  was  resolved  that  the 
investigation  above  referred  to  should  be  repeated,  making 


WOKK  OF  THE  INTERNATIONAL  COMMISSION    219 

use  of  other  quartz  plates  not  subject  to  the  defect  men- 
tioned. 

On  the  motion  of  Messrs.  Dupont  and  Jobin  it  was 
resolved  to  employ  plates  the  rotation  values  of  which 
shall  cover  the  entire  scale  of  the  saccharimeter,  one  levo- 
rotatory  and  four  dextro-rotatory  plates,  the  thickness  of 
which  is  at  the  same  time  to  be  given,  so  that  the  plates 
shall  remain  serviceable  when  the  normal  weights  shall 
be  changed. 

In  determining  the  value  of  the  plates  there  shall  be 
employed  not  only  the  normal  temperature  of  20°  C.  but, 
on  the  motion  of  Messrs.  Wiley  and  Wiechmann,  also  of 
30°  C.,  in  order  to  take  into  due  account  the  condition 
of  warmer  countries.  In  employing  apparatus  with  quartz- 
wedge  compensation  the  changes  shall  be  studied  which 
the  saccharimeter  itself  suffers  in  consequence  of  variations 
of  temperature.  As  source  of  light  there  shall  be  employed 
only  yellow  sodium  light  or  light  sufficiently  purified  by 
ray-filters. 

Upon  the  motion  of  Dr.  Hermann,  of  Hamburg,  it  was 
furthermore  agreed  to  emphasize  specifically  in  the  protocol 
that  the  Commission  had  thus  far  made  no  such  changes 
in  the  normal  weight  for  polariscopes  which  could  influence 
the  results  of  polarization  in  the  least.  This  had  been 
mentioned  already  in  the  protocol  of  the  Hamburg  session 
of  June  12th,  1897. 

(2.)  Desirability  of  examining  raw  beet  sugars  for  trade 
purposes  according  to  the  inversion  method. 

Those  present  were  unanimously  of  the  opinion  that  the 
question  should,  in  general,  be  decided  in  the  negative. 
Exception  should  be  made  only  in  case  of  the  products 
obtained  in  making  sugar  from  molasses;  with  these  it  was 
recommended  to  make  determinations  of  sugar  and  of 
raffinose. 

(3.)  Discussion  of  >  applications  of  the  Deutsche  Zucker- 
Export-Vereine. 


220  SUGAR  ANALYSIS 

Dr.  Hermann  suggested  that  uniformity  in  analytical 
methods  should  even  now  be  striven  for  as  much  as  possible, 
and  the  presiding  officer  was  requested  to  prepare,  with 
the  assistance  of  the  members  of  the  Commission,  a  clear 
compilation  of  analytical  methods  which  are  in  vogue  in 
the  different  countries,  and  also  to  prepare  a  resume*  of  the 
directions  which  are  to  be  followed  in  cases  of  differences 
in  analysis.  Basing  on  these  documents,  the  attempt 
shall  be  made  to  secure  International  acceptance  of  a 
uniform  method  of  procedure. 

THIRD  SESSION:  Paris,  France,  July  24th,  1900. 

(1.)  Normal  sugar-weight  to  be  adopted  for  saccharimeters 
of  German  make  when  the  metric  flask  is  used. 

The  Imperial  Physical-Technical  Institute  has,  by  its 
communication  dated  October  19th,  1898,  called  attention 
to  the  fact  that  an  exact  conversion  of  the  normal  weight 
26.048  grams  for  Mohr's  cubic  centimeters  at  17.5°  C. 
corresponds  to  26.01  grams  (not  26.00)  metric  volume  at 
20°  C.,  determined  in  air  with  brass  weights. 

The  Commission  decided  that  in  consideration  of  the 
insignificance  of  the  deviation  the  normal  weight  of  26.00 
grams  shall  henceforth  be  adopted  for  100  metric  cubic 
centimeters,  at  20°  C.,  determined  in  air  with  brass 
weights. 

(2.)  Examination  and  disposal  of  quartz  plates. 

Prof.  Herzfeld  reported  briefly  on  the  results  of  the 
examination  of  quartz  plates,  and  the  Commission  agreed 
that  these  quartz  plates  should  be  divided  among  the  nations 
represented.  For  the  United  States,  the  plates  were  to  be 
sent  to  the  Department  of  Agriculture,  at  Washington; 
for  France,  to  the  Syndicate  of  Sugar  Manufacturers; 
for  Belgium,  Holland,  Austria-Hungary,  and  Russia,  to 
the  Associations  of  Sugar  Manufacturers  represented  in  the 
session  by  delegates. 

(3.)  General  principles  governing  the  adjustment  of  saccha- 
rimeters. 


WORK  OF  THE  INTERNATIONAL  COMMISSION    221 

On  motion  of  Messrs.  Camuset  and  Saillard,  the  fol- 
lowing was  adopted : 

"  The  Convention  declares  it  to  be  necessary  that  the 
rotation  of  chemically  pure  sugar  be  accepted  as  the  funda- 
mental basis  in  saccharimetry. 

"  The  chemically  pure  sugar  which  is  to  be  employed 
for  this  purpose  shall  everywhere  be  prepared  according 
to  the  same  method  which  is  as  follows  (method  of  the 
English  chemists) : 

"  Purest  commercial  sugar  is  to  be  further  purified  in  the 
following  manner:  A  hot  saturated  aqueous  solution  is 
prepared  and  the  sugar  precipitated  with  absolute  ethyl 
alcohol;  the  sugar  is  carefully  spun  in  a  small  centrifugal 
machine  and  washed  in  the  latter  with  some  alcohol.  The 
sugar  thus  obtained  is  re-dissolved  in  water,  again  the 
saturated  solution  is  precipitated  with  alcohol  and  washed 
as  above.  The  product  of  the  second  centrifugaling  is 
dried  between  blotting  paper  and  preserved  in  glass  vessels 
for  use.  The  moisture  still  contained  in  the  sugar  is  deter- 
mined and  taken  into  account  when  weighing  the  sugar 
which  is  to  be  used." 

The  Convention  furthermore  decided  that  central 
stations  shall  be  designated  in  each  country  which  are  to  be 
charged  with  the  preparation  and  the  distribution  of  chem- 
ically pure  sugar.  Wherever  this  arrangement  is  not  feasible, 
quartz  plates,  the  values  of  which  have  been  determined 
by  means  of  chemically  pure  sugar,  shall  serve  for  the  con- 
trol of  saccharimeters. 

Mention  should  be  made  of  the  fact  that  in  the  dis- 
cussion on  this  topic,  it  was  remarked,  on  the  one  hand, 
that  the  preparation  of  chemically  pure  sugar  is  not  an 
easy  task,  and  that  in  countries  having  hot  climates,  sugar 
is  dried  with  difficulty  and  hence  is  not  stable,  and  hardly 
available  for  transportation.  Thereupon  it  was  pointed 
out  that  the  above  control,  by  means  of  chemically  pure 
sugar,  should,  as  a  rule,  apply  only  to  the  central  stations 


222  SUGA&  ANALYSIS 

which  are  to  test  the  correctness  of  saccharimeters;  for 
those  who  execute  commercial  analyses,  the  repeated  con- 
trol of  the  instruments  is  to  be  accomplished,  now  as  before, 
by  means  of  quartz  plates. 

Concerning  the  working  temperature  the  following 
resolution  of  Mr.  Fran$ois  Sachs  was  unanimously  adopted: 

"  In  general,  all  sugar  tests  shall  be  made  at  20°  C. 

"  The  adjustment  of  the  saccharimeter  shall  be  made 
at  20°  C.  One  dissolves  (for  instruments  arranged  for  the 
German  normal  weight)  26.00  grams  of  pure  sugar  in  a 
100  metric  cubic  centimeters  flask,*  weighing  to  be  made 
in  air,  with  brass  weights,  and  polarizes  the  solution  in  a 
room  the  temperature  of  which  is  also  20°  C.  Under  these 
conditions  the  instrument  must  indicate  exactly  100.00 

"  The  temperature  of  all  sugar  solutions  to  be  tested  is 
always  to  be  kept  at  20°  C.,  while  they  are  being  prepared 
and  while  they  are  being  polarized. 

"  However,  for  those  countries  the  temperature  of  which 
is  ger  orally  higher,  it  is  permissible  that  the  saccharimeters 
be  adjusted  at  30°  C.  (or  at  any  other  suitable  temperature), 
under  the  conditions  specified  above,  and  providing  that 
the  analysis  of  sugar  be  made  at  that  same  temperature.'' 

Objections  were  raised  against  the  universal  normal 
weight  20.00  grams  by  Mr.  Frangois  Sachs  as  well  as  by 
Mr.  Strohmer.  In  consequence,  it  was  resolved  not  to 
undertake  the  introduction  of  the  same,  but  to  adopt  the 
resolution : 

"The  general  International  introduction  of  a  uniform 
normal  weight  is  desirable." 

It  was  furthermore  resolved,  on  the  basis  of  the  proposi- 
tion of  Mr.  Strohmer,  to  observe  the  following  rules  in 
raw  sugar  analysis. 

*  Or  during  the  period  of  transition,  26.048  grams  in  100  Mohr's 
cubic  centimeters. 


WORK  OF  THE  INTERNATIONAL  COMMISSION    223 


I.     POLARIZATION. 

In  effecting  the  polarization  of  substances  containing 
sugar,  half-shade  instruments  only  are  to  be  employed. 

During  the  operation  the  apparatus  must  be  in  a  fixed, 
unchangeable  position,  and  so  far  removed  from  the  source 
of  light  that  the  polarizing  Nicol  is  not  warmed  by  the  same. 

As  source  of  light  there  are  to  be  recommended  lamps 
with  intense  flame  (gas  triple-burner  with  metallic  cylinder, 
lens  and  reflector;  gas  lamp  with  Auer  burner;  electric 
lamp;  petroleum  duplex  lamp;  sodium  light). 

The  chemist  must  satisfy  himself,  before  and  after  the 
observation,  of  the  correctness  of  the  apparatus  (by  means 
of  correct  quartz  plates)  and  in  regard  to  the  constancy 
of  the  light;  he  must  also  satisfy  himself  as  to  the  correct- 
ness of  the  weights,  of  the  polarization  flasks,  the  observa- 
tion tubes  and  the  cover  glasses.  (Scratched  cover  glasses 
must  not  be  used.) 

Several  readings  are  to  be  made  and  the  mean  thereof 
taken,  but  any  one  individual  reading  must  not  be  selected. 

II.    SUGAR  ANALYSIS. 

1.  Sucrose.  To  make  a  polarization,  the  whole  normal 
weight  for  100  cubic  centimeters  is  to  be  used,  or  a  multiple 
thereof  for  any  corresponding  volume. 

As  clarifying  and  decolorizing  reagents  there  may  be 
used:  subacetate  of  lead,  prepared  according  to  the  German 
Pharmacopoeia  (three  parts  by  weight  of  acetate  of  lead, 
one  part  by  weight  of  oxide  of  lead,  ten  parts  by  weight  of 
water),  Scheibler's  alumina  cream,  concentrated  solution 
of  alum.  Bone-black  and  decolorizing  powders  are  to  be 
absolutely  excluded. 

After  bringing  the  solution  exactly  to  the  mark  and  after 
wiping  out  the  neck  of  the  flask  with  filter  paper,  all  of  the 
well-shaken,  clarified  sugar  solution  is  poured  upon  a  dry, 


224  SUGAE  ANALYSIS 

rapidly  filtering  filter.  The  first  portions  of  the  filtrate 
are  to  be  thrown  away  and  the  balance,  which  must  be 
perfectly  clear,  is  to  be  used  for  polarization. 

2.  Water.     In  normal  beet  sugars  the  water  determina- 
tion is  to  be  made  at  105°  to  110°  C. 

For  abnormal  beet  sugars,  there  is  no  commercial  method 
for  the  determination  of  water. 

3.  Ash.     To  determine  the  ash-content  in  raw  sugars 
the  determination  is  to  be  made  according  to  Scheibler's 
method,    employing     pure    concentrated    sulphuric    acid. 
For  an  ash  determination  at  least  3  grams  of  the  sample 
are  to  be  used.     The  incineration  is  to  be  carried  out  in 
platinum  dishes,   by  means  of  platinum  or  clay  muffles, 
at  the  lowest  possible  temperature  (not  above  750°  C.). 

From  the  weight  of  the  sulphated  ash  thus  obtained, 
10  per  cent  is  to  be  deducted   and  the  ash-content,  thus 
•  corrected,  is  to  be  recorded  in  the  certificate. 

4.  Alkalinity.     As,  according  to  the  most  recent  investi- 
gations, the  alkalinity  of  raw  sugars  is  not  always  a  criterion 
of  their  durability,  the  Commission  abstains  from  propos- 
ing definite  directions  for  the  execution  of  the  investigations. 

5.  Invert    Sugar.     The    quantitative    determination   of 
invert  sugar  in  raw  sugars  is  to  be  made  according  to  the 
method  of  Dr.  A.  Herzfeld.     (Zeitschrift  des  Vereins  fur  die 
Riibenzucker-Industrie  des  Deutschen  Reiches,  1886,  pp.  6  &  7.) 

Furthermore   the   following   resolutions   were   adopted: 

The  Commission  declares  that  only  well  closed  glass 
vessels  will  ensure  the  stability  of  samples. 

To  obtain  correct  results  it  is  desirable  that  the  samples 
contain  at  least  200  grams  of  material. 

All  of  the  above  resolutions  were  adopted  unanimously 
by  those  present. 

FOURTH  SESSION.     Berlin,    Germany,    June   4th,    1903. 

(1.)  Professor  Herzfeld  outlined  the  previous  work  of  the 
Commission. 

The  sets  of  quartz  plates  which  had  been  selected  by 


WOEK  OF  THE  INTERNATIONAL  COMMISSION    225 

the  Physikalisch-Technische  Reichsanstalt  in  Berlin,  and 
which  had  been  tested  in  the  laboratory  of  the  Verein  der 
Deutschen  Zuckerindustrie  as  to  their  sugar  value,  have  been 
distributed  to  proper  central  stations  of  the  countries  inter- 
ested, and  there  kept  at  the  disposal  of  ch  mists.  These 
plates  have  been  tested  in  almost  all  of  the  countries  which 
have  received  the  sets,  and  have  been  found  correct.  Some 
of  these  stations  have  thus  far  not  made  a  report  as  to  the 
result  of  this  re-examination,  and  such  a  report  is  therefore 
requested. 

Execution  of  the  Paris  agreement,  according  to  which 
chemically  pure  sugar  is  to  be  used  for  the  adjustment 
of  polariscopes  and  for  the  testing  of  plates,  has  in 
some  countries,  met  with  difficulties  because  they  could 
not  succeed  in  preparing  chemically  pure  sugar.  The 
laboratory  at  Berlin,  therefore,  offers  to  furnish  chemically 
pure  sugar. 

In  the  determination  of  invert  sugar  a  difficulty  has 
arisen,  inasmuch  as  the  English  chemists  have  of  late  again 
declared  against  the  clarification  with  basic  lead  acetate; 
the  Commission  will  therefore  have  to  seek  means  and 
methods  to  prevent,  in  this  respect,  loss  of  uniformity  now 
secured  in  the  methods  of  analysis. 

The  day's  proceedings  furthermore  covered  reports, 
concerning: 

I.  Practical  experiences  made  with  the  uniform  methods 
of  analysis  agreed  upon  in  Paris. 

II.  The  valuation  of  "  Sand  "  and  "  Krystallzucker  " 
in  International  trade. 

III.  Introduction    of   International    uniform    directions 
for  sampling  raw  sugars. 

IV.  and  V.  Influence   of  temperature   on  the   specific 
rotation  of  sucrose,  and  introduction  of  temperature-correc- 
tions when  the  temperature  of  observation  differs  from  the 
temperature  of  20°  C.,,  which  has  been  accepted  as  the  normal 
temperature. 


226  SUGAR  ANALYSIS 

VI.  Determination   of   the   sugar   subject   to   duty   or 
bounty  contained  in  saccharine  products  and  fruit  preserves. 

VII.  Chemical  control  as  an  aid  to  the  "  Entrepot " 
system,  sanctioned  by  the  Brussels  Convention. 

FIFTH  SESSION:  Bern,  Switzerland,  August  3d  and 
4th,  1906. 

(1.)  The  Chairman  in  a  review  of  the  achievements  of  the 
Commission  designated  the  duties  of  the  Commission  to  be 
purely  analytical. 

The  Commission  has  for  its  object  the  regulation  of  the 
methods  of  sugar  analysis  and  endeavors  to  secure  the 
working  of  chemists  according  to  uniform  and  the  best 
methods,  but  the"Commission  does  not  undertake  to  establish 
trade-customs.  The  Commission  does  not  recognize  resolu- 
tions carried  by  majority  vote,  it  is  in  fact  necessary  that  at 
least  the  representatives  of  the  most  important  countries 
interested  in  sugar  be  in  accord  on  a  question  before  the  same 
is  presented  for  acceptance,  as  otherwise  no  reliance  can  be 
placed  on  the  recognition  of  the  resolutions  by  chemists. 

(2.)  Determination  of  a  method  of  preparing  Fehling's 
solution  as  well  as  the  manner  of  making  invert  sugar  determina- 
tions. 

Messrs.  Watt  and  Wiechmann  communicated  the  results 
of  their  investigations.  Mr.  Watt  preferred  the  volumetric 
method,  Mr.  Wiechmann  the  gravimetric  method  for  com- 
mercial analyses.  The  latter  moved  that  clarification  with 
basic  lead  acetate  shall  be  obligatory  for  the  examination 
of  syrups.  This  recommendation  was  endorsed  by  Messrs. 
Watt  and  Prinsen  Geerligs  and  thereupon  also  by  the  entire 
Commission. 

The  Chairman  reported  on  tests  made  for  the  compar- 
ison of  Violette's  and  Fehling's  solution,  which  had  not 
yet  been  completed.  He  announced  that  Mr.  Munson, 
the  Chairman  of  the  Association  of  American  Agricultural 
Chemists  had,  through  intervention  of  Mr.  Wiechmann, 
sent  him  a  resolution  of  the  Association  named,  wherein 


WORK  OF  THE  INTERNATIONAL  COMMISSION    227 

the  same  expressed  the  wish  to  work  hand  in  hand  with  the 
Commission  in  the  matter  of  securing  a  uniform  alkaline 
copper  solution. 

Mr.  Pellet  also  presented  a  paper  on  this  subject  which 
was  published  in  the  Sucrerie  Indigene  as  well  as  in  the 
Deutsche  Vereinszeitschrift. 

Mr.  Strohmer  promised  a  later  report  of  his  experiments 
bearing  on  this  question  which,  at  present,  are  not  yet 
completed.  He  recommended  retaining  for  the  present  the 
so-called  Herzfeld  method, 

Mr.  Watt  declared  himself  against  basic  lead  acetate 
clarification  for  solid  sugars. 

Mr.  Sachs  refrained  from  voting. 

Mr.  Saillard  as  well  as  Mr.  Dupont  expressed  themselves 
in  favor  of  retaining  basic  lead  acetate  clarification  as  long 
as  the  present  method  was  used. 

Mr.  Pellet  declared  himself  against  the  use  of  basic  lead 
acetate  as  a  clarifying  reagent. 

Mr.  Schukow  favored  this  clarification  in  commercial 
analysis. 

Mr.  Watt  handed  in  the  following  declaration: 

"  The  difference  between  the  amount  of  the  reducing 
substances  in  the  clarified  and  the  non-clarified  solu- 
tion of  beet  sugar  lies  so  closely  within  the  limits  of  the 
errors  of  observation,  that  a  clarification  is  unneces- 
sary; but  in  products  which  contain  a  large  amount 
of  glucose  a  clarification  is  of  great  importance." 

Mr.  Herzfeld  was  of  the  opinion  that  he  could  not  accept 
the  first  half  of  the  declaration,  the  difference  being  indeed 
a  small  one  but  giving  rise  to  considerable  annoyance  in 
trade. 

Mr.  von  Buchka  proposed  to  defer  the  question  of  the 
composition  of  Fehling's  solution  and  to  have  the  same 
studied  further  by  a  separate  commission. 

Mr.  Geerligs  expressed  himself  in  favor  of  the  basic 
lead  acetate  clarification  for  syrups. 


228  SUGAR  ANALYSIS 

Mr.  Main  spoke  against  the  basic  lead  acetate  clarifica- 
tion in  raw  sugars. 

The  Chairman  proposed  to  request  the  chemists  of  Great 
Britain  to  discuss  this  question  in  a  separate  conference 
once  more  with  delegates  of  the  Commission  in  order  to 
try,  in  this  manner,  to  bring  about  an  agreement. 

The  proposition  of  the  Chairman  was  accepted  by  the 
Commission  and  a  sub-commission  was  appointed,  consist- 
ing of  Messrs.  Strohmer,  Saillard,  Sachs,  Schukow,  van 
Ekenstein,  Watt,  Main,  von  Buchka  and  Herzfeld,  this 
sub-commission  to  take  part  in  the  conference  with  the 
chemists  of  Great  Britain. 

The  Chairman  agreed  to  ask  for  the  intervention  of  the 
German  Export  Societies  to  the  end  that  the  conference 
might  soon  be  called  in  London. 

The  question  of  Fehling's  solution  should  be  subjected 
to  further  study. 

(3.)  Uniform  International  directions  for  sampling  sugar 
products. 

(4.)  Resolution  concerning  a  uniform  form  and  manner 
of  expression  of  certificates  of  analysis  for  the  International 
sugar  trade. 

Mr.   Saillard  presented   the   following   resolutions: 

1.  As  long  as  it  is  not  settled  that  the  degree  of  alkalinity 
is  a  sure  criterion  for  the  keeping  qualities  of  sugars,  the 
determination    of    alkalinity    shall    not    be    considered   in 
International  commerce. 

2.  The   Commission   shall   determine   upon  a   uniform 
method  by  which  the  trade   yield    (Rendement)   for  the 
sugar  is  to  be  calculated,  in  establishing  scientific  molasses 
coefficients  for  the  impurities  (ash  and  invert  sugar)  the 
relation  of  which  is  used  in  the  certificates  of  analysis. 

3.  The  state  laboratories  shall  also  take  part  in  the 
endeavors  to  bring  about  uniformity,  in  order  to  cause  a 
disappearance  of  the  differences  between  trade  ash  determina- 
tions and  Regie  ash  determinations.     (France.) 


WORK  OF  THE  INTERNATIONAL  COMMISSION    229 

These  resolutions  were  accepted  by  the  Commission,  and 
the  Commission  also  decided,  for  the  present,  not  to  endorse 
any  specific  form  of  certificate  of  analysis. 

(5.)  Avoidance  of  the  precipitate  error  in  optical  sugar 
analysis. 

(6.)  Suggestions  for  the  preparation  of  unchangeable  color 
standards  in  place  of  the  raw  sugar  used  for  the  Dutch  standards. 

After  a  report  by  the  Chairman  on  the  substitution  of 
samples  of  colored  glasses  for  the  Dutch  standards,  and  a 
discussion  of  the  question,  the  Commission  unanimously 
expressed  the  wish  that  the  valuation  of  sugar  according 
to  its  color  might  soon  be  abandoned  altogether,  because 
this  practice  was  to  be  condemned  from  the  scientific  as 
well  as  from  the  practical  point  of  view. 

(7.)  Concerning  a  method  to  be  recommended  for  the  deter- 
mination of  the  sugar-content  of  beets. 

The  Commission  was  of  the  opinion  and  unanimously 
adopted  the  resolution,  that  the  aqueous  digestion  method 
for  the  determination  of  the  sugar-content  of  the  beets  if 
it  be  executed  with  due  regard  to  the  precautions  suggested 
by  Pellet,  Sachs  and  others,  was  to  be  recommended  in 
preference  to  the  alcohol  method.  The  Commission  charged 
Messrs.  Pellet,  Sachs  and  Herles  with  presenting  detailed 
working  directions  of  the  method. 

(8.)  A  uniform  International  sugar-weight. 

After  a  review  by  the  Chairman  of  the  prior  discussions 
on  this  topic,  the  introduction  by  Mr.  Dupont  of  a  proposi- 
tion to  accept  20.00  grams  as  the  normal  weight,  and  a  thor- 
ough debate  of  the  proposition,  the  Chairman  put  the 
question  to  those  present  concerning  the  desirability  of 
retaining  26.00  grams  as  the  normal  sugar-weight  for  sac- 
charimeters. 

Mr.  Sachs  replied  in  the  affirmative. 

Mr.  Saillard  did  not  consider  it  necessary  that  all  coun- 
tries should  have  the  same  normal  weight  in  order  to  have 
a  uniform  method. 


230  SUGAR  ANALYSIS 

On  the  question  being  put  by  the  Chairman,  the  repre- 
sentatives present  of  America,  Java,  Great  Britain,  Russia, 
and  Austria-Hungary  declared  themselves  against  the 
normal  weight  of  20.00  grams  and  for  the  normal  weight  of 
26.00  grams. 

Mr.  Sachs  declared  himself  in  accord  with  Mr.  Saillard 
to  admit  20.00  grams,  but  not  to  prescribe  it. 

9.  Conference  regarding  measures  to  secure  an  Inter- 
nationally valid  uniform  method  of  beet  seed  valuation. 

On  the  recommendation  of  the  Chairman  the  proposi- 
tion was  accepted  that  the  Commission  should  not  occupy 
itself  with  the  establishment  of  standards  (Normen),  but 
only  with  the  establishment  of  methods  of  investigation. 

Hereupon  a  sub-commission  was  chosen  to  work  out 
uniform  methods  of  examination;  Mr.  F.  Strohmer  was 
appointed  chairman  of  the  same. 

The  following  were  elected  members  of  the  suo-com- 
mission:  Messrs.  Strohmer,  President;  Saillard,  Boussaud 
(Paris),  Sachs,  Schukow,  Mtiller  (Halle),  Krliger  (Bern- 
burg),  Herzfeld,  Raatz,  von  Dippe,  Heine,  Briem,  Neumann 
and  Herles. 

The  Commission  was  authorized  to  increase  its  numbers 
by  the  election  of  further  members. 

SIXTH  SESSION:     London,   England,   May  31st.,    1909. 

(1.)  Report  of  the  work  of  the  International  Commission 
since  its  tast  session. 

Mr.  Herzfeld  reported  that  the  results  of  newer  investi- 
gations speak  against  the  views  expressed  by  the  members 
of  the  Commission  in  Bern,  making  obligatory  the  clarifica- 
tion with  basic  lead  acetate  for  the  determination  of  invert 
sugar  in  syrups.  For  this  reason  this  matter  was  therefore 
that  day  given  place  on  the  program  to  permit  of  another 
resolution.  All  other  resolutions  taken  in  Bern  have  been 
put  into  practice. 

Prof.  Villavecchia  in  Rome  has  agreed,  in  a  letter 
addressed  to  the  Chairman,  that  the  Commission  shall 


WORK  OF  THE  INTERNATIONAL  COMMISSION    231 

be  called  in  consultation  in  case  an  International  Commis- 
sion of  the  Government  works  out  directions  for  sugar 
analysis 

Agreeable  to  the  resolution  taken  in  Bern,  a  compila- 
tion of  the  proceedings  to  date  of  the  Commission  has  thus 
far  been  printed  only  in  German.  Copies  of  this  pamphlet 
will  be  sent  to  the  members  of  the  Commission  by  the 
Chairman  if  they  so  desire.  A  compilation  of  the  resolu- 
tions adopted  thus  far  by  the  Commission,  which  had  been 
prepared  by  Mr.  Wiechmann  of  New  York,  was  distributed. 
Messrs.  Francois  Sachs  and  Saillard  promised  to  publish 
such  a  compilation  in  French. 

Mr.  Strohmer,  Vienna,  then  reported  on  the  doings  of 
the  Sub-Commission  for  Uniform  Methods  of  Beet-Seed 
Analysis  appointed  in  Bern,  which  had  met  under  his 
direction  in  Vienna  on  May  24,  1907,  but  which  had  taken 
definite  resolutions  only  with  regard  to  uniform  methods 
for  the  determination  of  water  and  the  determination  of 
impurities.  A  report  concerning  the  session  of  the  Sub- 
Commission  has  already  been  published  in  the  technical 
journals. 

At  the  suggestion  of  the  referee,  the  International  Commis- 
sion decided  that  the  introduction  of  uniform  methods  of  beet- 
seed  examination  was  to  be  postponed  until  it  should  be  settled 
whether,  and  in  what  manner,  the  present  standards  (Normen) 
are  to  be  changed. 

(2.)  Unification  of  the  tables  for  the  calculation  of  the 
contents  of  sugar  solutions  from  their  density. 

Messrs.  Saillard,  Paris,  and  von  Buchka,  Berlin,  reported 
on  this  topic.  Their  findings  will  be  published  in  full 
in  the  technical  journals. 

On  the  motion  of  Mr.  Sachs,  seconded  by  Messrs.  Saillard, 
Prinsen  Geerligs,  Strohmer,  Neumann,  and  Pellet,  the  Com- 
mission voted  unanimously  to  accept  a  single  table  as  standard 
at  the  temperature  o/>200  C.,  which  is  to  be  based  upon  the 
official  German  table.  From  this,  other  tables  may  be  calculated 


232  SUGAR  ANALYSIS 

at  other  temperatures,  for  instance,  at  15°  C.,  17.5°  C.,  30°  C., 
etc.j  as  well  as  a  table  according  to  the  Mohr  system,  20°  C.: 
20°  C. 

(3.)  Propositions  for  the  use  of  uniform  clarifying  reagents 
for  the  analysis  of  sugar  products, 

Referees:  Messrs.  Prinsen  Geerligs,  Java,  and  Francois 
Sachs,  Brussels.  Their  findings  will  also  be  published  in 
the  technical  journals.  In  this  connection  Mr.  Herles  rec- 
ommended basic  lead  nitrate  as  a  clarifying  re-agent. 

After  an  extensive  debate  in  which  all  delegates  took  part, 
the  Commission  unanimously  decided  that  for  the  direct  polariza- 
tion of  solutions  of  raw  sugar  products,  basic  lead  acetate 
shall  also  in  future  be  used  for  clarification,  but  not  in  excess. 
For  fluid  sugars  (syrup  and  molasses),  basic  lead  acetate  may 
not  be  employed  for  the  determination  of  invert  sugar,  but  only 
neutral  lead  acetate  as  a  clarifying  reagent. 

An  agreement  could  not  be  reached  concerning  the  clarify- 
ing of  solutions  of  solid  raw  sugars  for  the  purpose  of  the 
determination  of  invert  sugar,  as  the  English  chemists 
remained  firm  in  their  former  position  to  effect  no  clarifica- 
tion whatever  for  the  determination  of  invert  sugar. 

(4.)  Agreement  as  to  a  uniform  nomenclature  for  the  products 
of  sugar  manufacture,  especially  in  view  of  the  food  laws. 

Referee:  Mr.  Strohmer,  Vienna,  made  a  report  on  this 
topic  which  will  be  published  in  the  technical  journals. 
On  the  motion  of  the  referee,  and  of  Messrs.  Saillard  and 
Silz,  a  resolution  in  this  matter  was,  for  the  present,  post- 
poned. 

(5.)  Dr.  Wiley,  of  Washington,  read  two  articles  by 
Messrs.  A.  Hugh  Byran  and  C.  A.  Browne,  New  York, 
concerning  the  conditions  of  basic  lead  acetate  clarification 
and  on  temperature  corrections  in  raw  sugar  polarizations, 
which  are  to  be  published  at  once.  In  consequence  of  the 
declaration  of  Dr.  Wiley  that  in  order  to  avoid  temperature 
corrections,  the  American  Government  Laboratories  for 
sugar  analysis  are  soon  to  be  provided  with  cooling  arrange- 


WORK  OF  THE  INTERNATIONAL  COMMISSION    233 

ments  in  order  that  the  polarizations  shall  be  made  exclu- 
sively at  the  normal  temperature  of  20°  C.,  the  Commission 
avoided  voting  on  the  resolution  of  Mr.  Browne,  New  York, 
in  which  the  avoidance  of  any  and  every  temperature 
correction  in  raw  sugar  analysis  is  demanded.  (See  article 
by  Mr.  Browne  in  the  technical  journals.)  Prior  to  this, 
this  resolution  had  been  fully  established  by  Mr.  Home, 
representing  Mr.  Browne. 

An  article  by  Mr.  Home,  on  the  use  of  dry  basic  lead 
acetate  clarification  in  sugar  analysis,  could  not  be  read  in  this 
session  of  the  Commission.  This  article  has  been  published 
in  the  Zeitschrift  des  Vereins  der  Deutschen  Zucker-Industrie. 

SEVENTH  SESSION:    New  York,  September  10th,  1912. 

(1.)  Report  on  the  work  done  since  the  last  session. 

Mr.  Saillard  reported  that  he  and  Mr.  Sachs  have  con- 
ferred about  the  publication  of  a  compilation  of  the  pro- 
ceedings of  all  sessions  of  the  Commission  in  French,  and 
expressed  the  belief  that  this  will  be  achieved  in  time  for 
the  next  session. 

The  German  Imperial  Bureau  of  Standards  (Normal- 
eichungsamt)  promised  to  prepare  tables  for  the  determina- 
tion of  the  percentage  composition  of  sugar  solutions  from 
their  specific  gravity  at  different  temperatures,  as  was 
requested  at  the  London  conference. 

The  following  resolution  was  unanimously  adopted: 

"  Owing  to  the  declaration  of  Dr.  Wiley  at  the  6th  Session 
of  the  International  Commission  for  Uniform  Methods  of 
Sugar  Analysis  in  London,  1909,  that,  in  order  to  avoid 
temperature  corrections  the  American  Government  Laboratories 
for  sugar  analysis  are  soon  to  be  provided  with  cooling  arrange- 
ments in  order  that  polarizations  shall  be  made  exclusively  at 
the  normal  temperature  of  20°  C.,  and  to  the  fact  that  this 
declaration  has  not  yet  been  carried  into  effect,  this  Commis- 
sion again  expresses  the  opinion  that  official  polarizations  of 
raw  sugar  products  shall  be  made  only  at  the  constant  standard 
temperature  20°  C.,  the  presence  of  invert  sugar  and  other 


234  SUGAK  ANALYSIS 

impurities  precluding  the  use  of  formula  and  tables,  which 
have  been  elaborated  for  correcting  the  polarization  of  pure 
sucrose  for  changes  of  temperature." 

(2.)  Uniform  methods  of  sucrose  determination  in  the  raw 
materials  of  sugar  manufacture. 

Mr.  Saillard,  at  the  behest  of  the  Syndicate  of  Sugar 
Manufacturers,  of  France,  explained  that  the  trade  in  beets 
and  the  trade  with  molasses  does  not,  for  France,  bear  the 
same  International  character  as  the  trade  in  sugar,  and 
requested  that  the  International  Commission  treat  analytical 
methods  for  beets  and  molasses  only  from  the  viewpoint 
of  analytical  chemistry. 

Upon  the  recommendation  of  Mr.  Herzfeld,  after  a 
short  debate,  the  Commission  refrained  from  officially 
endorsing  uniform  methods  of  sucrose  determination  in 
beets  and  in  sugar  cane.  It  was  agreed,  by  publication 
in  the  technical  journals  of  the  various  countries,  to  bring 
the  reports  of  Messrs.  Strohmer,  Sachs,  Saillard,  Wiechmann, 
Prinsen  Geerligs,  and  Herles,  which  were  read  before  the 
meeting,  to  the  notice  of  those  interested,  and  to  call  atten- 
tion to  the  propositions  of  the  referees. 

(3.)  Uniform  methods  for  the  determination  of  the  specific 
gravity  of  sugar  solutions. 

Mr.  Saillard  and  Mr.  von  Buchka  presented  reports 
on  this  topic;  these  reports  are  to  be  published;  Messrs. 
Weinstein,  Strohmer,  and  Saillard  participated  in  the  debate 
which  followed. 

It  was  agreed  to  publish  the  reports  of  the  referees  and 
the  following  resolutions  were  adopted.  On  motion  of 
Mr.  Strohmer  that: 

"  The  International  Commission  for  Uniform  Methods 
of  Sugar  Analysis  expresses  the  wish  that  the  various  countries 
may  prescribe  a  uniform  temperature  for  the  density  determina- 
tions of  sugar  solutions. 

"  In  trade  analyses  the  use  of  temperature  correction 
tables  should  be  dispensed  with,  as  far  as  possible." 


WORK  OF  THE  INTERNATIONAL  COMMISSION    235 

On  motion  of  Mr.  von  Buchka  that: 

"  The  normal  temperature  of  +20°  C.  is  to  be  retained 
for  trade  analyses. 

In  density  determinations  of  aqueous  sugar  solutions,  the 
density  obtained  at  normal  temperature  shall  be  referred  to  the 
density  of  water  at  +4°  C.  and  to  vacuo. 

In  density  determinations  made  by  weighing,  the  results 

20 
must  be  calculated  to  -r^°  C.  and  to  vacuo.     To  effect  this  it  will 

be  desirable  to  use  tables  prepared  for  the  purpose." 

Mr.  Saillard  agreed  to  the  latter  part  of  the  resolution, 
provided  that  in  France  the  normal  temperature  there 

customary,  namely  -^-°  C.,  be  retained  in  place  of  -j-°  C. 

(4.)  Resolution  concerning  a  further  examination  of  the 
inversion-constants  of  the  double  polarization  (Clerget-Herz- 
feld)  method. 

Mr.  Herzfeld  reported,  that  although  the  correctness 
of  the  constant  132.66  at  20°  C.  for  a  solution  which  contains 
the  German  half  normal  weight  of  pure  sucrose  has  been 
confirmed  by  numerous  chemists  and,  finally  by  an  Inter- 
national Commission  of  Chemists,  who  worked  in  Berlin 
in  1910,  yet,  on  the  basis  of  more  recent  investigations,  it 
seems  to  him  desirable  to  re-test  the  accuracy  of  this  con- 
stant in  as  far  as  its  application  in  the  analysis  of  beet- 
molasses  is  concerned.  A  committee  consisting  of  Messrs. 
Bates,  Bryan,  Browne,  Prinsen  Gee'rligs,  Saillard,  Sachs, 
and  Strohmer  is  appointed  to  re-test  this  constant. 

The  following  reports  were  also  made  and  the  following 
resolutions  adopted: 

Mr.  A.  Hugh  Bryan  made  a  report  on  the  necessity  of 
using  light-ray  niters  for  polarizing  high  grade  sugars, 
and  on  his  motion  the  following  resolution  was  adopted: 

"  Wherever  white  light  is  used  in  polarimetric  determina- 
tions, the  same  must  be  filtered  through  a  solution  of  potassium 
Bichromate  of  such  a  concentration  that  the  percentage  content 


236  SUGAE  ANALYSIS 

of  the  solution  multiplied  by  the  length  of  the  column  of  the 
solution  in  centimeters  is  equal  to  nine." 

Furthermore,  Mr.  Bates  reported  on  investigations 
conducted  by  the  Bureau  of  Standards  and  Weights,  which 
led  to  the  conclusion  that  the  one-hundred  point  of  sac- 
charimeters  provided  with  Ventzke  scales  at  present  accepted, 
is  not  quite  correct.  On  his  motion  the  following  resolu- 
tion was  adopted: 

"  Inasmuch  as  recent  investigations  tend  to  question  the 
validity  of  the  present  100°  point  of  saccharimeters,  and 
inasmuch  as  it  is  desirable  that  the  Commission  recognize 
and  fix  a  transformation  factor  from  absolute  degrees  to  Ventzke 
degrees,  the  Chairman  is  hereby  empowered  to  appoint  a 
Committee  of  three  to  fully  investigate  this  question  and  report 
at  the  next  official  meeting." 

At  the  suggestion  of  the  Chairman,  Messrs.  Bates, 
Schonrock,  and  Strohmer  were  elected  as  members  of  this 
sub-committee. 


TABLES 


I. 

RELATION  BETWEEN  SPECIFIC,  GRAVITY,  DEGREES 
BRIX  AND  DEGREES  BAUME,  FOR  PURE  SUGAR 
SOLUTIONS  FROM  0  TO  100  PER  CENT. 

MATEGCZEK  AND  SCHEIBLER. 
(Temperature  17.5°  C.  =  63.5°  F.) 


FORMULA  OF  VON  LORENZ. 
SPECIFIC  GRAVITY  AND  DEGREES  BRIX 

Let  d=  specific  gravity,  s  =  degrees  Brix. 
For  the  range  of: 
no     Q*°  n  •  a     29374+14« 

°   ~35    BnX d  =29375 -100s 

35° -70°  Brix...  ^35036+43* 


70° -100°  Brix..  .  .d 


35163 -100s 
42067  -f  92s 


42908 -100s 

DEGREES    BRIX   AND   SPECIFIC    GRAVITY 
For  the  range  of: 
1.00000-1.15411 


1  1 541 1      1  ^088  ,  -35163d -35036 

88 s~        100d+43 

,0^00     I**-**  ._42908d  -42067 

100d+92     ' 

SPECIFIC    GRAVITY   AND    DEGREES   BAUME. 
Let  d  =specific  gravity,  n  =degrees  Baum6. 

146.78 
146.78  -n' 
DEGREES   BAUME    AND    SPECIFIC    GRAVITY 


DEGREES   BRIX   AND   DEGREES   BAUME. 

Let  s  =  degrees  Brix,  n  =  degrees  Baum6. 
For  the  range  of' 

0.00°-19.60°  Baume  ......  .  .  s  =  10+2097n 

1195—  n 

19.60°-38.12°  Baume  ........................................ 


38.12°-  52.56°  Baume  ........................................  s  =1342+457-2" 

t  306.3  -n 

DEGREES    BAUME   AND    DEGREES    BRIX. 
For  the  range  of: 


35°-70°Brix..  488s  -433 

s  +814.5 

70°-100°  Brix  ................................  n  =306.3s-1342 

s  +457.2 

239 


240 


SUGAR  ANALYSIS 


Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

0.0 

1.00000 

0.00 

4.0 

.01570 

2   27 

0.1 

1.00038 

0.06 

4.1 

.01610 

2.33 

0.2 

1.00077 

0.11 

4.2 

.01650 

2.38 

0.3 

1.00116 

0.17 

4.3 

.01690 

2.44 

0.4 

1.00155 

0.23 

4.4 

.01730 

2.50 

0.5 

1.00193 

0.28 

4.5 

.01770 

2.55 

0.6 

1.00232 

0.34 

4.6 

.01810 

2.61 

0.7 

1.00271 

0.40 

4.7 

.01850 

2.67 

0.8 

1.00310 

0.45 

4.8 

.01890 

2  72 

0.9 

1.00349 

0.51 

4.9 

.01930 

2.78 

1.0 

1.00388 

0.57 

5.0 

.01970 

2.84 

1.1 

1.00427 

0.63 

5.1 

.02010 

2.89 

1.2 

1.00466 

0.68 

5.2 

.02051 

2.95 

1.3 

1.00505 

0.74 

5.3 

1.02091 

3.01 

1.4 

1.00544 

0.80 

5.4 

1.02131 

3.06 

1.5 

1.00583 

0.85 

5.5 

1.02171 

3.12 

1.6 

1.00622 

0.91 

5.6 

1.02211 

3.18 

1.7 

1.00662 

0.97 

5.7 

1.02252 

3.23 

1.8 

1.00701 

1.02 

5.8 

1.02292 

3.29 

1.9 

1.00740 

1.08 

5.9 

1.02333 

3.35 

2.0 

1.00779 

1.14 

6.0 

1.02373 

3.40 

2.1 

1.00818 

1.19 

6.1 

1.02413 

3.46 

2.2 

1.00858 

1.25 

6.2 

1.02454 

3.52 

2.3 

1.00897 

1.31 

6.3 

1.02494 

3.57 

2.4 

1.00936 

1.36 

6.4 

1.02535 

3.63 

2.5 

1.00976 

1.42 

6.5 

1.02575 

3.69 

2.6 

1.01015 

1.48 

6.6 

1.02616 

3.74 

2.7 

1.01055 

1.53 

6.7 

1.02657 

3.80 

2.8 

1.01094 

1.59 

6.8 

1.02697 

3.86 

2.9 

1.01134 

1.65 

6.9 

1.02738 

3.91 

3.0 

1.01173 

1.70 

7.0 

1.02779 

3.97 

3.1 

1.01213 

1.76 

7.1 

1.02819 

4.03 

3.2 

1.01252 

1.82 

7.2 

1.02860 

4.08 

3.3 

1.01292 

1.87 

7.3 

1.02901 

4.14 

3.4 

1.01332 

1.93 

7.4 

1.02942 

4.20 

3.5 

1.01371 

1.99 

7.5 

1.02983 

4.25 

3.6 

1.01411 

2.04 

7.6 

1.03024 

4.31 

3.7 

1.01451 

2.10 

7.7 

1.03064 

4.37 

3.8 

1.01491 

2.16 

7.8 

1.03105 

4.42 

3.9 

1.01531 

2.21 

7.9 

1.03146 

4.48 

TABLES 


241 


Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
BaumS. 

Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

8.0 

1.03187 

4.53 

13.0 

1.05276 

7.36 

8.1 

1.03228 

4.59 

13.1 

1.05318 

7.41 

8.2 

1.03270 

4.65 

13.2 

1.05361 

7.47 

8.3 

.03311 

4.70 

13.3 

1.05404 

7.53 

8.4 

.03352 

4.76 

13.4 

1.05446 

7.58 

8.5 

.03393 

4.82 

13.5 

1.05489 

7.64 

8.6 

.03434 

4.87 

13.6 

1.05532 

7.69 

8.7 

.03475 

4.93 

13.7 

1.05574 

7.75 

8.8 

1.03517 

4.99 

13.8 

1.05617 

7.81 

8.9 

1.03558 

5.04 

13.9 

1.05660 

7.86 

9.0 

1.03599 

5.10 

14.0 

1.05703 

7.92 

9.1 

1.03640 

5.16 

14.1 

1.05746 

7.98 

9.2 

1.03682 

5.21 

14.2 

1.05789 

8.03 

9.3 

1.03723 

5.27 

14.3 

1.05831 

8.09 

9.4 

1.03765 

5.33 

14.4 

1.05874 

8.14 

9.5 

1.03806 

5.38 

14.5 

1.05917 

8.20 

9.6 

1.03848 

5.44 

14.6 

1.05960 

8.26 

9.7 

1.03889 

5.50 

14.7 

1.06003 

8.31 

9.8 

1.03931 

5.55 

14.8 

1.06047 

8.37 

9.9 

1.03972 

5.61 

14.9 

1.06090 

8.43 

10.0 

1.04014 

5.67 

15.0 

.06133 

8.48 

10.1 

1.04055 

5.72 

15.1 

.06176 

8.54 

10.2 

1.04097 

5.78 

15.2 

.06219 

8.59 

10.3 

1.04139 

5.83 

15.3 

.06262 

8.65 

10.4 

1.04180 

5.89 

15.4 

.06306 

8.71 

10.5 

1.04222 

5.95 

15.5 

.06349 

8.76 

10.6 

1.04264 

6.00 

15.6 

.06392 

8.82 

10.7 

1.04306 

6.06 

15.7 

.06436 

8.88 

10.8 

1.04348 

6.12 

15.8 

.06479 

8.93 

10.9 

1.04390 

6.17 

15.9 

.06522 

8.99 

11.0 

1.04431 

6.23 

16.0 

.06566 

9.04 

11.1 

1.04473 

6.29 

16.1 

.06609 

9.10 

11.2 

1.04515 

6.34 

16.2 

.06653 

9.16 

11.3 

1.04557 

6.40 

16.3 

.06696 

9.21 

11.4 

1.04599 

6.46 

16.4 

.06740 

9.27 

11.5 

1.04641 

6.51 

16.5 

.06783 

9.33 

11.6 

1.04683 

6.57 

16.6 

.06827 

9.38 

11.7 

1.04726 

6.62 

16.7 

.06871 

9.44 

11.8 

1.04768 

6.68 

16.8 

.06914 

9.49 

11.9 

1.04810 

6.74 

16.9 

.06958 

9.55 

12.0 

1.04852 

6.79 

17.0 

1.07002 

9.61 

12.1 

1.04894 

6.85 

17.1 

1.07046 

9.66 

12.2 

1.04937 

6.91 

17.2 

1.07090 

9.72 

12.3 

1.04979 

6.96 

17.3 

1.07133 

9.77 

12.4 

1.05021 

7.02 

17  .4 

1.07177 

9.83 

12.5 

1.05064 

7.08 

17.5 

1.07221 

9.89 

12.6 

1.05106 

,    7.13 

17.6 

1.07265 

9.94 

12.7 

1.05149 

7.19 

17.7 

1.07309 

10.00 

12.8 

1.05191 

7.24 

17.8 

1.07358 

10.06 

12.9 

1.05233 

7.30 

17.9 

1.07397 

10.11 

242 


SUGAE  ANALYSIS 


Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baume. 

Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baume. 

18.0 

1.07441 

10.17 

23.0 

1.09686 

12.96 

18.1 

1.07485 

10.22 

23.1 

1.09732 

13.02 

18.2 

1.07530 

10.28 

23.2 

1.09777 

13.07 

18.3 

1.07574 

10.33 

23.3 

1.09823 

13.13 

18.4 

1.07618 

10.39 

23.4 

1.09869 

13.19 

18.5 

1.07662 

10.45 

23.5 

1.09915 

13.24 

18.6 

1.07706 

10.50 

23.6 

1.09961 

13.30 

18.7 

1.07751 

10.56 

23.7 

1  .  10007 

13.35 

18.8 

1.07795 

10.62 

23.8 

1.10053 

13.41 

18.9 

1.07839 

10.67 

23.9 

1.10099 

13.46 

19.0 

1.07884 

10.73 

24.0 

1  .  10145 

13.52 

19.1 

1.07928 

10.78 

24.1 

1.10191 

13.58 

19.2 

1.07973 

10.84 

24  2 

1  .  10237 

13.63 

19.3 

1.08017 

10.90 

24^3 

1  .  10283 

13.69 

19.4 

1.08062 

10.95 

24.4 

1  .  10329 

13.74 

19.5 

1.08106 

11.01 

24.5 

1  .  10375 

13.80 

19.6 

1.08151 

11.06 

24.6 

1.10421 

13.85 

19.7 

1.08196 

11.12 

24.7 

1.10468 

13.91 

19.8 

1.08240 

11.18 

24.8 

1.10514 

13.96 

19.9 

1.08285 

11.23 

24.9 

1  .  10560 

14.02 

20.0 

1.08329 

11.29 

25.0 

1.10607 

14.08 

20.1 

1.08374 

11.34 

25.1 

1  .  10653 

14.13 

J20.2 

1.08419 

11.40 

25.2 

1.10700 

14.19 

20.3 

1.08464 

11.45 

25.3 

1  .  10746 

14.24 

20.4 

.08509 

11.51 

25.4 

1  .  10793 

14.30 

20.5 

.08553 

11.57 

25.5 

1  .  10839 

14.35 

20.6 

.08599 

11.62 

25.6 

1.10886 

14.41 

20.7 

.08643 

11.68 

25.7 

1  .  10932 

14.47 

20.8 

.08688 

11.73 

25.8 

1  .  10979 

14.52 

20.9 

.08733 

11.79 

25.9 

1.11026 

14.58 

21.0 

1.08778 

11.85 

26.0 

1.11072 

14.63 

21.1 

1.08824 

11.90 

26.1 

1.11119 

14.69 

21.2 

1.08869 

11.96 

26.2 

1.11166 

14.74 

21.3 

1.08914 

12.01 

26.3 

1.11213 

14.80 

21.4 

1.08959 

12.07 

26.4 

1.11259 

14.85 

21.5 

1.09004 

12.13 

26.5 

1.11306 

14.91 

21.6 

1.09049 

12.18 

26.6 

1.11353 

14.97 

21.7 

1.09095 

12.24 

26.7 

1.11400 

15.02 

21.8 

1.09140 

12.29 

26.8 

1.11447 

15.08 

21.9 

1.09185 

12.35 

26.9 

1.11494 

15.13 

22.0 

.09231 

12.40 

27.0 

1.11541 

15.19 

22.1 

.09276 

12.46 

27.1 

1.11588 

15.24 

22.2 

.09321 

12.52 

27.2 

1.11635 

15.30 

22.3 

.09367 

12.57 

27.3 

1.11682 

15.35 

22.4 

.09412 

12.63 

27.4 

1.11729 

15.41 

22.5 

.09458 

12.68 

27.5 

1.11776 

15.46 

22.6 

1.09503 

12.74 

27.6 

1.11824 

15.52 

22.7 

1.09549 

12.80 

27.7 

1.11871 

15.58 

.  22.8 

1.09595 

12.85 

27.8 

1.11918 

15.63 

22.9 

1.09640 

12.91 

27.9 

1.11965 

15.69 

TABLES 


243 


Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

Degrees 
Brix. 

Specific 
Gravity. 

Degrees 

Bauroe. 

28.0 

1.12013 

15.74 

33.0 

1.14423 

18.50 

28.1 

1.12060 

15.80 

33.1 

.14472 

18.56 

28.2 

1.12107 

15.85 

33.2 

.14521 

18.61 

28.3 

1.12155 

15.91 

33.3 

.  14570 

18.67 

28.4 

1  .  12202 

15.96 

33.4 

.  14620 

18.72 

28.5 

1  .  12250 

16.02 

33.5 

.  14669 

18.78 

28.6 

1.12297 

16.07 

33.6 

1.14718 

18.83 

28.7 

1  .  12345 

16.13 

33.7 

1  .  14767 

18.89 

28.8 

1  .  12393 

16.18 

33.8 

1.14817 

18.94 

28.9 

1  .  12440 

16.24 

33.9 

1  .  14866 

19.00 

29.0 

1.12488 

16.30 

34.0 

1  .  14915 

19.05 

29.1 

1.12536 

16.35 

34.1 

1.14965 

19.11 

29.2 

1.12583 

16.41 

34.2 

1.15014 

19.16 

29.3 

1.12631 

16.46 

34.3 

1  .  15064 

19.22 

29.4 

1  .  12679 

16.52 

34.4 

1.15113 

19.27 

29.5 

1  .  12727 

16.57 

34.5 

1.15163 

19.33 

29.6 

1  .  12775 

16.63 

34.6 

1.15213 

19.38 

29.7 

1  .  12823 

16.68 

34.7 

1  .  15262 

19.44 

29.8 

1.12871 

16.74 

34.8 

1.15312 

19.49 

29.9 

1  .  12919 

16.79 

34.9  * 

1  .  15362 

19.55 

30.0 

.12967 

16.85 

35.0 

1.15411 

19.60 

30.1 

.13015 

16.90 

35.1 

1  .  15461 

19.66 

30.2 

.13063 

16.96 

35.2 

1.15511 

19.71 

30.3 

.13111 

17.01 

35.3 

1  .  15561 

19.76 

30.4 

.13159 

17.07 

35.4 

1.15611 

19.82 

30.5 

.  13207 

17.12 

35.5 

1  .  15661 

19.87 

30.6 

1  .  13255 

17.18 

35.6 

1.15710 

19.93 

30.7 

1.13304 

17.23 

35.7 

1  .  15760 

19.98 

30.8 

1.13352 

17.29 

35.8 

1.15810 

20.04 

30.9 

1.13400 

17.35 

35.9 

1  .  15861 

20.09 

31.0 

1.13449 

17.40 

36.0 

1.15911 

20.15 

31.1 

1.13497 

17.46 

36.1 

1  .  15961 

20.20 

31.2 

1  .  13545 

17.51 

36.2 

1.16011 

20.26 

31.3 

1  .  13594 

17.57 

36.3 

.16061 

20.31 

31.4 

1.13642 

17.62 

36.4 

.16111 

20.37 

31.5 

1.13691 

17.68 

36.5 

.16162 

20.42 

31.6 

1.13740 

17.73 

36.6 

.16212 

20.48 

31.7 

1.13788 

17.79 

36.7 

.  16262 

20.53 

31.8 

1.13837 

17.84 

36.8 

.16313 

20.59 

31.9 

1  .  13885 

17.90 

36.9 

1  .  16363 

20.64 

32.0 

1  .  13934 

17.95 

37.0 

1.16413 

20.70 

32.1 

1.13983 

18.01 

37.1 

1  .  16464 

20.75 

32.2 

1.14032 

18.06 

37.2 

1.16514 

20.80 

32.3 

1.14081 

18.12 

37.3 

1.16565 

20.86 

32.4 

1.14129 

18.17 

37.4 

1.16616 

20.91 

32.5 

1  .  14178 

18.23 

37.5 

1.16666 

20.97 

32.6 

1  .  14227 

,  18.28 

37.6 

1.16717 

21.02 

32.7 

1.14276 

18.34 

37.7 

1.16768 

21.08 

32.8 

1.14325 

18.39 

37.8 

1.16818 

21.13 

32.9 

1.14374 

18.45 

37.9 

1  .  16869 

21.19 

244 


SUGAR  ANALYSIS 


Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

38.0 

1  .  16920 

21.24 

43.0 

1.19505 

23.96 

38.1 

1.16971 

21.30 

43.1 

1  .  19558 

24.01 

38.2 

1  .  17022 

21.35 

43.2 

1.19611 

24.07 

38.3 

1  .  17072 

21.40 

43.3 

1  .  19663 

24.12 

38.4 

1.17132 

21.46 

43.4 

1.19716 

24.17 

38.5 

1.17174 

21.51 

43.5 

1.19769 

24.23 

38.6 

1.17225 

21.57 

43.6 

1  .  19822 

24.28 

38.7 

1.17276 

21.62 

43.7 

1.19875 

24.34 

38.8    . 

1.17327 

21.68 

43.8 

1  .  19927 

24.39 

38.9 

1.17379 

21.73 

43.9 

1  .  19980 

24.44 

39.0 

1.17430 

21.79 

44.0 

1.20033 

24.50 

39.1 

1.17481 

21.84 

44.1 

.20086 

24.55 

39.2 

1.17532 

21.90 

44.2 

.20139 

24.61 

39.3 

1.17583 

21.95 

44.3 

.20192 

24.66 

39.4 

1.17635 

22.00 

44.4 

.20245 

24.71 

39.5 

1  .  17686 

22.06 

44.5 

.20299 

24.77 

39.6 

1  .  17737 

22.11 

44.6 

.20352 

24.82 

39.7 

1.17789 

22.17 

44.7 

.20405 

24.88 

39.8 

1.17840 

22.22 

44.8 

.20458 

24.93 

39.9 

1  .  17892 

22.28 

44.9 

.20512 

24.98 

40.0 

1  .  17943 

22.33 

45.0 

.20565 

25.04 

40.1 

1  .  17995 

22.38 

45.1 

.20618 

25.09 

40.2 

1.18046 

22.44 

45.2 

.20672 

25.14 

40.3 

1.18098 

22.49 

45.3 

1.20725 

25.20 

40.4 

.18150 

22.55 

45.4 

1.20779 

25.25 

40.5 

.  18201 

22.60 

45.5 

1.20832 

25.31 

40.6 

.  18253 

22.66 

45.6 

1.20886 

25.36 

40.7 

.18305 

22.71 

45.7 

1.20939 

25.41 

40.8 

.18357 

22.77 

45.8 

1.20993 

25.47 

40.9 

.  18408 

22.82 

45.9 

1.21046 

25.52 

41.0 

.  18460 

22.87 

46.0 

1.21100 

25.57 

41.1 

.  18512 

22.93 

46.1 

1.21154 

25.63 

41.2 

.18564 

22.98 

46.2 

1.21208 

25.68 

41.3 

.18616 

23.04 

46.3 

1.21261 

25.74 

41.4 

1.18668 

23.09 

46.4 

.21315 

25.79 

41.5 

1  .  18720 

23.15 

46.5 

.21369 

25.84 

41.6 

1  .  18772 

23.20 

46.6 

.21423 

25.90 

41.7 

1.18824 

23.25 

46.7 

.21477 

25.95 

41.8 

1.18877 

23.31 

46.8 

.21531 

26.00 

41.9 

1.18929 

23.36 

46.9 

.21585 

26.06 

42.0 

1.18981 

23.42 

47.0 

1.21639 

26.11 

42.1 

1  .  19033 

23.47 

47.1 

1.21693 

26.17 

42.2 

1.19086 

23.52 

47.2     . 

1.21747 

26.22 

42.3 

1.19138 

23.58 

47.3 

1.21802 

26.27 

42.4 

1.19190 

23.63 

47.4 

1.21856 

26.33 

42.5 

1  .  19243 

23.69 

47.5 

1.21910 

26.38 

42.6 

1  .  19295 

23.74 

47.6 

1.21964 

26.43 

42.7 

1.19348 

23.79 

47.7 

1.22019 

26.49 

42.8 

1  .  19400 

23.85 

47.8 

1.22073 

26.54 

42.9 

1  .  19453 

23.90 

47.9 

1.22127 

26.59 

TABLES 


245 


Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

48.0 

1.22182 

26.65 

53.0 

1.24951 

29.31 

48.1 

1.22236 

26.70 

53.1 

1.25008 

29.36 

48.2 

1.22291 

26.75 

53.2 

1.25064 

29.42 

48.3 

1.22345 

26.81 

53.3 

1.25120 

29.47 

48.4 

1.22400 

26.86 

53.4 

1.25177 

29.52 

48.5 

.22455 

26.92 

53.5 

1.25233 

29.57 

48.6 

.22509 

26.97 

53.6 

1.25290 

29.63 

48.7 

.22564 

27.02 

53.7 

1.25347 

29.68 

48.8 

.22619 

27.08 

53.8 

1.25403 

29.73 

48.9 

.22673 

27.13 

53.9 

1.25460 

29.79 

49.0 

.22728 

27.18 

54.0 

1.25517 

29.84 

49.1 

.22783 

27.24 

54.1 

1.25573 

29.89 

49.2 

.22838 

27.29 

54.2 

1.25630 

29.94 

49.3 

.22893 

27.34 

54.3 

1.25687 

30.00 

49.4 

.22948 

27.40 

54.4 

1.25744 

30.05 

49.5 

.23003 

27.45 

54.5 

1.25801' 

30.10 

49.6 

.23058 

27.50 

54.6 

1.25857 

30.16 

49.7 

.23113 

27.56 

54.7 

1.25914 

30.21 

49.8 

.23168 

27.61 

54.8 

1.25971 

30.26 

49.9 

.23223 

27.66 

54.9 

1.26028 

30.31 

50.0 

1.23283 

27.72 

55.0 

1.26086 

30.37 

50.1 

1.23334 

27.77 

55.1 

1.26143 

30.42 

50.2 

1.23389 

27.82 

55.2 

1.26200 

30.47 

50.3 

1.23444 

27.88 

55.3 

1.26257 

30.53 

50.4 

1.23499 

27.93 

55.4 

1.26314 

30.58 

50.5 

1.23555 

27.98 

55.5 

1.26372 

30.63 

50.6 

1.23610 

28.04 

55.6 

1.26429 

30.68 

50.7 

1.23666 

28.09 

55.7 

1.26486 

30.74 

50.8 

1.23721 

28.14 

55.8 

1.26544 

30.79 

50.9 

1.23777 

28.20 

55.9 

1.26601 

30.84 

51.0 

1.23832 

28.25 

56.0 

1.26658 

30.89 

51.1 

1.23888 

28.30 

56.1 

1.26716 

30.95 

51.2 

1.23943 

28.36 

56.2 

1.26773 

31.00 

51.3 

1.23999 

28.41 

56.3 

1.26831 

31.05 

51.4 

1.24055 

28.46 

56.4 

.26889 

31.10 

51.5 

.24111 

28.51 

56.5 

.26946 

31.16 

51.6 

.24166 

28.57 

56.6 

.27004 

31.21 

51.7 

.24222 

28.62 

56.7 

.27062 

31.26 

51.8 

.24278 

28.67 

56.8 

.27120 

31.31 

51.9 

.24334 

28.73 

56.9 

.27177 

31.37 

52.0 

.24390 

28.78 

57.0 

.27235 

31.42 

52.1 

.24446 

28.83 

57.1 

.27293 

31.47 

52.2 

.24502 

28.89 

57.2 

.27351 

31.52 

52.3 

.24558 

28.94 

57.3 

.27409 

31.58 

52.4 

1.24614 

28.99 

57.4 

.27467 

31.63 

52.5 

1.24670 

29.05 

57.5 

.27525 

31.68 

52.6 

1.24726 

,29.10 

57.6 

.27583 

31.73 

52.7 

1.24782 

29.15 

57.7 

1.27641 

31.79 

52.8 

1.24839 

29.20 

57.8 

1.27699 

31.84 

52.9 

1.24895 

29.26 

57.9 

1.27758 

31.89 

246 


SUGAR  ANALYSIS 


Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baume1. 

58.0 

.27816 

31.94 

63.0 

1.30777 

34.54 

58.1 

.27874 

32.00 

63.1 

1.30837 

34.59 

58.2 

.27932 

32.05 

63.2 

1.30897 

34.65 

58.3 

.27991 

32.10 

63.3 

1.30958 

34.70 

58.4 

.28049 

32.15 

63.4 

1.31018 

34.75 

58.5 

.28107 

32.20 

63.5 

1.31078 

34.80 

58.6 

.28166 

32.26 

63.6 

1.31139 

34.85 

58.7 

.28224 

32.31 

63.7 

1.31199 

34.90 

58.8 

.28283 

32.36 

63.8 

1.31260 

34.96 

58.9 

.28342 

32.41 

63.9 

1.31320 

35.01 

59.0 

.28400 

32.47 

64.0 

1.31381 

35.06 

59.1 

.28459 

32.52 

64.1 

1.31442 

35.11 

59.2 

.28518 

32.57 

64.2 

1.31502 

35.16 

59.3 

.28576 

32.62 

64.3 

1.31563 

35.21 

59.4 

.28635 

32.67 

64.4 

1.31624 

35.27 

59.5 

.28694 

32.73 

64.5 

1.31684 

35.32 

59.6 

.28753 

32.78 

64.6 

1.31745 

35.37 

59.7 

.28812 

32.83 

64.7 

1.31806 

35.42 

59.8 

.28871 

32.88 

64.8 

1.31867 

35.47 

59.9 

.28930 

32.93 

64.9 

1.31928 

35.52 

60.0 

1.28989 

32.99 

65.0 

1.31989 

35.57 

60.1 

1.29048 

33.04 

65.1 

1.32050 

35.63 

60.2 

1.29107 

33.09 

65.2 

1.32111 

35.68 

60.3 

1.29166 

33.14 

65.3 

1.32172 

35.73 

60.4 

1.29225 

33.20 

65.4 

1.32233 

35.78 

60.5 

1.29284 

33.25 

65.5 

1.32294 

35.83 

60.6 

1.29343 

33.30 

65.6 

1.32355 

35.88 

60.7 

1.29403 

33.35 

65.7 

1.32417 

35.93 

60.8 

1.29462 

33.40 

65.8 

1.32478 

35.98 

60.9 

1.29521 

33.46 

65.9 

1.32539 

36.04 

61.0 

1.29581 

33.51 

66.0 

1.32601 

36.09 

61.1 

1.29640 

33.56 

66.1 

1.32662 

36.14 

61.2 

1.29700 

33.61 

66.2 

1.32724 

36.19 

61.3 

1.29759 

33.66 

66.3 

1.32785 

36.24 

61.4 

1.29819 

33.71 

66.4 

.32847 

36.29 

61.5 

.29878 

33.77 

66.5 

.32908 

36.34 

61.6 

.29938 

33.82 

66.6 

.32970 

36.39 

61.7 

.29998 

33.87 

66.7 

.33031 

36.45 

61.8 

.30057 

33.92 

66.8 

.33093 

36.50 

61.9 

.30117 

33.97 

66.9 

.33155 

36.55 

62.0 

.30177 

34.03 

67.0 

.33217 

36.60 

62.1 

.30237 

34.08 

67.1 

.33278 

36.65 

62.2 

.30297 

34.13 

67.2 

.33340 

36.70 

62.3 

.30356 

34.18 

67.3 

.33402 

36.75 

62.4 

.30416 

34.23 

67.4 

.33464 

36.80 

62.5 

1.30476 

34.28 

67.5 

.33526 

36.85 

62.6 

1.30536 

34.34 

67.6 

.33588 

36.90 

62.7 

1.30596 

34.39 

67.7 

.33650 

36.96 

62.8 

1.30657 

34.44 

67.8 

.33712 

37.01 

62.9 

1.30717 

34.49 

67.9 

.33774 

37.06 

TABLES 


247 


Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baume. 

Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baumfi. 

68.0 

.33836 

37.11 

73.0 

1.36995 

39.64 

68.1 

.33899 

37.16 

73.1 

1  .  37059 

39.69 

68.2 

.33961 

37.21 

73.2 

1.37124 

39.74 

68.3 

.34023 

37.26 

73.3 

1.37188 

39.79 

68.4 

.34085 

37.31 

73.4 

1.37252 

39.84 

68.5 

1.34148 

37.36 

73.5 

1.37317 

39.89 

68.6 

1.34210 

37.41 

73.6 

1.37381 

39.94 

68.7 

1.34273 

37.47 

73.7 

.37446 

39.99 

68.8 

1.34335 

37.52 

73.8 

.37510 

40.04 

68.9 

1.34398 

37.57 

73.9 

.37575 

40.09 

69.0 

1.34460 

37.62 

74.0 

.37639 

40.14 

69.1 

1.34523 

37.67 

74.1 

.37704 

40.19 

69.2 

1.34585 

37.72 

74.2 

.37768 

40.24 

69.3 

1.34648 

37.77 

74.3 

.37833 

40.29 

69.4 

1.34711 

37.82 

74.4 

.37898 

40.34 

69.5 

1.34774 

37.87 

74.5 

.37962 

40.39 

69.6 

.34836 

37.92 

74.6 

1.38027 

40.44 

69.7 

.34899 

37.97 

74.7 

1.38092 

40.49 

69.8 

.34962 

38.02 

74.8 

1.38157 

40.54 

69.9 

.35025 

38.07 

74.9 

1.38222 

40.59 

70.0 

.35088 

38.12 

75.0 

.38287 

40.64 

70.1 

.35151 

38.18 

75.1 

.38352 

40.69 

70.2 

.35214 

38.23 

75.2 

.38417 

40.74 

70.3 

1.35277 

38.28 

75.3 

.38482 

40.79 

70.4 

1.35340 

38.33 

75.4 

.38547 

40.84 

70.5 

1.35403 

38.38 

75.5 

.38612 

40.89 

70.6 

1.35466 

38.43 

75.6 

.38677 

40.94 

70.7 

1.35530 

38.48 

75.7 

.38743 

40.99 

70.8 

1.35593 

38.53 

75.8 

.38808 

41.04 

70.9 

1.35656 

38.58 

75.9 

.38873 

41.09 

71.0 

1.35720 

38.63 

76.0 

.38939 

41.14 

71.1 

1.35783 

38.68 

76.1 

.39004 

41.19 

71.2 

1.35847 

38.73 

76.2 

.39070 

41.24 

71.3 

1.35910 

38.78 

76.3 

.39135 

41.29 

71.4 

1.35974 

38.83 

76.4 

.39201 

41.33 

71.5 

.36037 

38.88 

76.5 

.39266 

41.38 

71.6 

.36101 

38.93 

76.6 

.39332 

41.43 

71.7 

.36164 

38.98 

76.7 

.39397 

41.48 

71.8 

.36228 

39.03 

76.8 

1.39463 

41.53 

71.9 

.36292 

39.08 

76.9 

1.39529 

41.58 

72.0 

1.36355 

39.13 

77.0 

1.39595 

41.63 

72.1 

1.36419 

39.19 

77.1 

1.39660 

41.68 

72.2 

1.36483 

39.24 

77.2 

1.39726 

41.73 

72.3 

1.36547 

39.29 

77.3 

1.39792 

41.78 

72.4 

1.36611 

39.34 

77.4 

1.39858 

41.83 

72.5 

1.36675 

39.39 

77.5 

1.39924 

41.88 

72.6 

1.36739 

•    39.44 

77.6 

1.39990 

41.93 

72.7 

1.36803 

39.49 

77.7 

1.40056 

41.98 

72.8 

1.36867 

39.54 

77.8 

1.40122 

42.03 

72.9 

1.36931 

39.59 

.     77.9 

1.40188 

42.08 

248 


SUGAR  ANALYSIS 


Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baumfi. 

78.0 

.40254 

42.13 

83.0 

.43614 

44.58 

78.1 

.40321 

42.18 

83.1 

.43682 

44.62 

78.2 

.40387 

42.23 

83.2 

.43750 

44.67 

78.3 

.40453 

42.28 

83.3 

.43819 

44.72 

78.4 

.40520 

42.32 

83.4 

.43887 

44.77 

78.5 

1.40586 

42.37 

83.5 

.43955 

44.82 

78.6 

1.40652 

42.42 

83.6 

1.44024 

44.87 

78.7 

1.40719 

42.47 

83.7 

1.44092 

44.91 

78.8 

1.40785 

42.52 

83.8 

1.44161 

44.96 

78.9 

1.40852 

42.57 

83.9 

1.44229 

45.01 

79.0 

.40918 

42.62 

84.0 

1.44298 

45.06 

79.1 

.40985 

42.67 

84.1 

1.44367 

45.11 

79.2 

.41052 

42.72 

84.2 

1.44435 

45.16 

79.3 

.41118 

42.77 

84.3 

1.44504 

45.21 

79.4 

.41185 

42.82 

84.4 

1.44573 

45.25 

79.5 

1.41252 

42.87 

84.5 

.44641 

45.30 

79.6 

1.41318 

42.92 

84.6 

.44710 

45.35 

79.7 

1.41385 

42.96 

84.7 

.44779 

45.40 

79.8 

1.41452 

43.01 

84.8 

.44848 

45.45 

79.9 

1.41519 

43.06 

84.9 

.44917 

45.49 

80.0 

1.41586 

43.11 

85.0 

.44986 

45.54 

80.1 

1.41653 

43.16 

85.1 

.45055 

45.59 

80.2 

1.41720 

43.21 

85.2 

1.45124 

45.64 

80.3 

1.41787 

43.26 

85.3 

1.45193 

45.69 

80.4 

1.41854 

43.31 

85.4 

1.45262 

45.74 

80.5 

1.41921 

43.36 

85.5 

1.45331 

45.78 

80.6 

1.41989 

43.41 

85.6 

1.45401 

45.83 

80.7 

1.42056 

43.45 

85.7 

1.45470 

45.88 

80.8 

1.42123 

43.50 

85.8 

1.45539 

45.93 

80.9 

1.42190 

43.55 

85.9 

i:  45609 

45.98 

81.0 

1.42258 

43.60 

86.0 

.45678 

46.02 

81.1 

1.42325 

43.65 

86.1 

.45748 

46.07 

81.2 

1.42393 

43.70 

86.2 

.45817 

46.12 

81.3 

1.42460 

43.75 

86.3 

.45887 

46.17 

81.4 

1.42528 

43.80 

86.4 

.45956 

46.22 

81.5 

1.42595 

43.85 

86.5 

.46026 

46.26 

81.6 

1.42663 

43.89 

86.6 

.46095 

46.31 

81.7 

1.42731 

43.94 

86.7 

.46165 

46.36 

81.8 

1.42798 

43.99 

86.8 

.46235 

46.41 

81.9 

1.42866 

44.04 

86.9 

.46304 

46.46 

82.0 

1.42934 

44.09 

87.0 

.46374 

46.50 

82.1 

1.43002 

44.14 

87.1 

.46444 

46.55 

82.2 

1.43070 

44.19 

87.2 

.46514 

46.60 

82.3 

1.43137 

44.24 

87.3 

.46584 

46.65 

82.4 

1.43205 

44.28 

87.4 

.46654 

46.69 

82.5 

1.43273 

44.33 

87.5 

.46724 

46.74 

82.6 

1.43341 

44.38 

87.6 

.46794 

46.79 

82.7 

1.43409 

44.43 

87.7 

.46864 

46.84 

82.8 

1.43478 

44.48 

87.8 

.46934 

46.88 

82.9 

1.43546 

44.53 

87.9 

1.47004 

46.93 

TABLES 


249 


Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

88.0 

1.47074 

46.98 

93.0 

1.50635 

49.34 

88.1 

1.47145 

47.03 

93.1 

1.50707 

49.39 

88.2 

1.47215 

47.08 

93.2 

1.50779 

49.43 

88.3 

1.47285 

47.12 

93.3 

1.50852 

49.48 

88.4 

1.47356 

47.17 

93.4 

1.50924 

49.53 

88.5 

1.47426 

47.22 

93.5 

.50996 

49.57 

88.6 

1.47496 

47.27 

93.6 

.51069 

49.62 

88.7 

1.47567 

47.31 

93.7 

.51141 

49.67 

88.8 

1.47637 

47.36 

93.8 

.51214 

49.71 

88.9 

1.47708 

47.41 

93.9 

.51286 

49.76 

89.0 

1.47778 

47.46 

94.0 

.51359 

49.81 

89.1 

1.47849 

47.50 

94.1 

.51431 

49.85 

89.2 

1.47920 

47.55 

94.2 

.51504 

49.90 

89.3 

1.47991 

47.60 

94.3 

.51577 

49.94 

89.4 

1.48061 

47.65 

94.4 

.51649 

49.99 

89.5 

1.48132 

47.69 

94.5 

.51722 

50.04 

89.6 

1.48203 

47.74 

94.6 

.51795 

50.08 

89.7 

1.48274 

47.79 

94.7 

1.51868 

50.13 

89.8 

1.48345 

47.83 

94.8 

1.51941 

50.18 

89.9 

1.48416 

47.88 

94.9 

1.52014 

50.22 

90.0 

1.48486 

47.93 

95.0 

1.52087 

50.27 

90.1 

1.48558 

47.98 

95.1 

1.52159 

50.32 

90.2 

1.48629 

48.02 

95.2 

1.52232 

50.36 

90.3 

1.48700 

48.07 

95.3 

1.52304 

50.41 

90.4 

1.48771 

48.12 

95.4 

1.52376 

50.45 

90.5 

1.48842 

48.17 

95.5 

1.52449 

50.50 

90.6 

1.48913 

48.21 

95.6 

1.52521 

50.55 

90.7 

1.48985 

48.26 

95.7 

1.52593 

50.59 

90.8 

1.49056 

48.31 

95.8 

1.52665 

50.64 

90.9 

1.49127 

48.35 

95.9 

1.52738 

50.69 

91.0 

1.49199 

48.40 

96.0 

1.52810 

50.73 

91.1 

1.49270 

48.45 

96.1 

1.52884 

50.78 

91.2 

1.49342 

48.50 

96.2 

1.52958 

50.82 

91.3 

1.49413 

48.54 

96.3 

1.53032 

50.87 

91.4 

1.49485 

48.59 

96.4 

1.53106 

50.92 

91.5 

1.49556 

48.64 

96.5 

1.53180 

50.96 

91.6 

1.49628 

48.68 

96.6 

1.53254 

51.01 

91.7 

1.49700 

48.73 

96.7 

1.53328 

51.05 

91.8 

1.49771 

48.78 

96.8 

1.53402 

51.10 

91.9 

1.49843 

48.82 

96.9 

1.53476 

51.15 

92.0 

1.49915 

48.87 

97.0 

1.53550 

51.19 

92.1 

1.49987 

48.92 

97.1 

1.53624 

51.24 

92.2 

1.50058 

48.96 

97.2 

1.53698 

51.28 

92.3 

1.50130 

49.01 

97.3 

1.53772 

51.33 

92.4 

1.50202 

49.06 

97.4 

1.53846 

51.38 

92.5 

1.50274 

49.11 

97.5 

1.53920 

51.42 

92.6 

1.50346 

,  49.15 

97.6 

1.53994 

51.47 

92.7 

1.50419 

49.20 

97.7 

1.54068 

51.51 

92.8 

1.50491 

49.25 

97.8 

1.54142 

51.56 

92.9 

1.50563 

49.29 

97.9 

1.54216 

51.60 

250 


SUGAK  ANALYSIS 


Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum<J. 

Degrees 
Brix. 

Specific 
Gravity. 

Degrees 
Baum6. 

98.0 

1.54290 

51.65 

99.0 

1.55040 

52.11 

98.1 

1.54365 

51.70 

99.1 

.55115 

52.15 

98.2 

1.54440 

51.74 

99.2 

.55189 

52.20 

98.3 

.54515 

51.79 

99.3 

.55264 

52.24 

98.4 

.54590 

51.83 

99.4 

.55338 

52.29 

98.5 

.54665 

51.88 

99.5 

.55413 

52.33 

98.6 

.54740 

51.92 

99.6 

.55487 

52.38 

98.7 

.54815 

51.97 

99.7 

.55562 

52.42 

98.8 

.54890 

52.01 

99.8 

.55636 

52.47 

98.9 

.54965 

52.06 

99.9 

.55711 

52.51 

100.0 

1.55785 

52.56 

II. 


CORRECTIONS  FOR  TEMPERATURE  IN  DETERMINATIONS 
BY   THE  SPECIFIC  GRAVITY  HYDROMETER. 

(CASAMAJOR.) 


252 


SUGAR  ANALYSIS 


II. 


Normal  Temperature:   15.0°  C. 

Normal  Temperature:  17.5°  C. 

Temperature  in 
Degrees 
Centigrade. 

Add  to  the  Reading 
of  the 
Hydrometer. 

Temperature  in 
Degrees 
Centigrade. 

Add  to  the  Reading 
of  the 
Hydrometer. 

9.90 

-0.0005 

.       7.5 

-0.0010 

15.00 

0.0000 

13.0 

-0.0005 

18.20 

+0.0005 

17.5 

0.0000 

20.75 

0.0010 

20.2 

+0.0005 

23.20 

0.0015 

23.0 

0.0010 

25.30 

0.0020 

25.0 

0.0015 

27.30 

0.0025 

27.0 

0.0020 

29.40 

0.0030 

29.0 

0.0025 

31.20 

0.0035 

31.0 

0.0030 

32.80 

0.0040 

32.5 

0.0035 

34.50 

0.0045 

34.7 

0.0040 

36.10 

0.0050 

36.2 

0.0045 

37.60 

0.0055 

37.4 

0.0050 

38.80 

0.0060 

39.0 

0.0055 

40.40 

0.0065 

40.5 

0.0060 

41.60 

0.0070 

42.0 

0.0065 

42.90 

0.0075 

43.4 

0.0070 

44.20 

0.0080 

44.2 

0.0075 

45.00 

0.0083 

45.0 

0.0080 

III. 

CORRECTIONS  FOR  TEMPERATURE  IN  DETERMINATIONS 
BY  THE  BRIX  HYDROMETER. 

Normal  Temperature  =  17.5°  C. 
(STAMMER.) 


254 


SUGAK  ANALYSIS 


III. 


03 

DEGREE  BRIX  OF  THE  SOLUTION. 

Ei 
«*-S 

LI 

0 

5 

10 

15 

20 

25 

30 

35 

40 

50 

60 

70 

75 

er 

The  degree  read  is  to  be  decreased  by  — 

0° 

0.17 

0.30 

0.41 

0.52 

0.62 

0.72 

0.82 

0.92 

0.98 

1.11 

1.22 

1.25 

1.29 

5 

0.23 

0.30 

0.37 

0.44 

0.52 

0.59 

0.65 

0.720.75 

0.80 

0.88 

0.91 

0.94 

10 

0.20 

0.26 

0.29 

0.33 

0.36 

0.39 

0.42 

0.45 

0.48 

0.50 

0.54'0.58 

0.61 

11 

0.18 

0.23 

0.26 

0.28 

0.31 

0.34 

0.36 

0.39 

0.41 

0.43 

0.470.50 

0.53 

12 

0.16 

0.20 

0.22 

0.24 

0.26 

0.29 

0.31 

0.33 

0.34 

0.36 

0.400.42 

0.46 

13 

0.14 

0.18 

0.19 

0.21 

0.22 

0.24 

0.26 

0.27 

0.28 

0.29 

0.330.35 

0.39 

14 

0.12 

0.15 

0.16 

0.17 

0.18 

0.19 

0.21 

0.22 

0.22 

0.23 

0.260.28 

0.32 

15 

0.09 

0.11 

0.12 

0.14 

0.14 

0.15 

0.16 

0.17 

0.16 

0.17 

0.190.21 

0.25 

16 

0.06 

0.07 

0.08 

0.09 

0.10 

0.10 

0.11 

0.12 

0.12 

0.12 

0.140.16 

0.18 

17 

0.02 

0.02 

0.03 

0.03 

0.03 

0.04 

0.04 

0.04 

0.04 

0.04 

0.05 

0.05 

0.06 

The  degree  read  is  to  be  increased  by  — 

I 

18 

0.02 

0.03 

0.03 

0.03 

0.03 

0.03 

0.03 

0.03 

0.03 

0.03 

0.03 

0.03 

0.02 

19 

0.06 

0.08 

0.08 

0.09 

0.09 

0.10 

0.10 

0.10 

0.10 

0.10 

0.10 

0.08 

0.06 

20 

0.11 

0.14 

0.15 

0.17 

0.17 

0.18 

0.18 

0.18 

0.19 

0.19 

0.18 

0.15 

0.11 

21 

0.16 

0.20 

0.22 

0.24 

0.24 

0.25 

0.25 

0.25 

0.26 

0.26 

0.25 

0.22 

0.18 

22 

0.21 

0.26 

0.29 

0.31 

0.31 

0.32 

0.32 

0.32 

0.33 

0.34 

0.32 

0.29 

0.25 

23 

0.27 

0.32 

0.35 

0.37 

0.38 

0.39 

0.39 

0.39 

0.40 

0.42 

0.39 

0.36 

0.33 

24 

0.32 

0.38 

0.41 

0.43 

0.44 

0.46 

0.46 

0.47 

0.47 

0.50 

0.46 

0.43 

0.40 

25 

0.37 

0.44 

0.47 

0.49 

0.51 

0.53 

0.54 

0.55 

0.55 

0.58 

0.54 

0.51 

0.48 

26     ,'0.43 

0.50 

0.54 

0.56 

0.58 

0.60 

0.61 

0.62 

0.62 

0.66 

0.62 

0.58 

0.55 

27     0.49 

0.57 

0.61 

0.63 

0.65 

0.68 

0.68 

0.69 

0.70 

0.74 

0.70 

0.65 

0.62 

28 

0.56 

0.64 

0.68 

0.70 

0.72 

0.76 

0.76 

0.78 

0.78 

0.82 

0.78 

0.72 

0.70 

29 

0.63 

0.71 

0.75 

0.78 

0.79 

0.84 

0.84 

0.86 

0.86 

0.90 

0.86 

0.80 

0.78 

30 

0.70 

0.78 

0.82 

0.87 

0.87 

0.92 

0.92 

0.94 

0.94 

0.98 

0.94 

0.88 

0.86 

35 

1.10 

1.17 

1.22 

1.24 

1.30 

1.32 

1.33 

1.35 

1.36 

1.39 

1.34 

1.27 

1.25 

40 

1.50 

1.61 

1.67 

1.71 

1.73 

1.79 

1.79 

1.80 

1.82 

1.83 

1.78 

1.69 

1.65 

50 

2.65 

2.71 

2.74 

2.78 

2.80 

2.80 

2.80 

2.80 

2.79 

2.70 

2.56 

2.51 

60 

3.87 

3.88 

3.88 

3.88 

3.88 

3.88 

3.88 

3.90 

3.82 

3.70 

3.43 

3.41 

70 

5.18 

5.20 

5.14 

5.13 

5.10 

5.08 

5.06 

4.90 

4.72 

4.47 

4.35 

80 

6.62 

6.59 

6.54 

6.46 

6.38 

6.30 

6.26 

6.06 

5.82 

5.50 

5.33 

IV. 

FACTORS. 
Arranged  for  Specific  Gravity  Determinations. 

Calculated  for  Wiechmann:    Sugar  Analysis,  from  the 
data  given  in  Table  I. 

26.048 
Factor  = 


Degree  BrixX  Specific  Gravity* 


256 


SUGAR  ANALYSIS 


IV. 


Specific 
Gravity. 

Factor. 

Specific 
Gravity. 

Factor. 

Specific 
Gravity. 

Factor. 

Specific 
Gravity. 

Factor. 

1   0950 

.053 

1.0980 

1.023 

.1010 

0.990 

1  .  1040 

0.959 

1.0955 

.047 

1.0985 

1.013 

.1015 

0.985 

1  .  1045 

0.955 

1.0960 

.042 

1.0990 

1.008 

.1020 

0.981 

1  .  1050 

0.950 

1.0965 

.037 

1.0995 

1.004 

.1025 

0.976 

1  .  1055 

0.946 

1.0970 

.033 

1.1000 

1.000 

.1030 

0.972 

1.1060 

0.942 

1.0975 

.028 

1.1005 

0.944 

.1035 

0.968 

V. 

FACTORS. 
Arranged  for  Brix  determinations. 

Calculated  for  Wiechmann:    Sugar  Analysis,  from  the 
data  given  in  Table  I. 

^  26.048 

Factor  = 


Degree  Brix  X  Specific  Gravity* 


258 


SUGAR  ANALYSIS 


V. 


u 

(5* 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

0 

.... 

260.381 

130.140 

86.726 

65.019 

51.996 

43.313 

37.111 

32  .  459 

28.842 

1 

25.947 

23.579 

21.606 

19.936 

18.505 

17.265 

16.179 

15.222 

14.370 

13.609 

2 

12.923 

12.303 

11.739 

11.225 

10.753 

10.318 

9.918 

9.547 

9.202 

8.881 

3 

8.582 

8.302 

8.039 

7.793 

7.560 

7.342 

7.135 

6.939 

6.754 

6.578 

4 

6.411 

6.253 

6.101 

5.957 

5.819 

5.688 

5.562 

5.441 

5.326 

5.215 

5 

5.109 

5.007 

4.909 

4.814 

4.723 

4.635 

4.551 

4.469 

4.390 

4.314 

6 

4.241 

4.170 

4.101 

4.034 

3.969 

3.907 

3.846 

3.787 

3.730 

3.674 

7 

3.621 

3.568 

3.517 

3.468 

3.419 

3.372 

3.327 

3.282 

3.239 

3.197 

8 

3.155 

3.115 

3.076 

3.038 

3.000 

2.964 

2.928 

2.893 

2.859 

2.826 

9 

2.794 

2.762 

2.731 

2.700 

2.671 

2.641 

2.613 

2.585 

2.557 

2.531 

10 

2.504 

2.479 

2.453 

2.428 

2.404 

2.380 

2.357 

2.334 

2.311 

2.289 

11 

2.268 

2.246 

2.225 

2.205 

2.185 

2.165 

2.145 

2.126 

2.107 

2.088 

12 

2.070 

2.052 

2.035 

2  017 

2.000 

1.983 

1.967 

1.951 

1.935 

1.919 

13 

1.903 

1.888 

1.873 

1.858 

1.843 

1.829 

1.815 

1.801 

1.787 

1.774 

14 

.760 

1.747 

1.734 

1.721 

1.709 

1.696 

1.684 

1.672 

1.660 

1.648 

15 

.636 

.625 

1.613 

1.602 

1.591 

1.580 

1.569 

1.559 

1.548 

1.538 

16 

.528 

.518 

1.508 

1.498 

1.488 

1.478 

1.469 

1.459 

1.450 

1.441 

17 

.432 

.423 

1.414 

1.405 

.397 

1.388 

1.380 

1.371 

1.363 

1.355 

18 

.347 

.339 

1.331 

1.323 

.315 

1.308 

1.300 

1.293 

1.285 

1.278 

19 

.271 

.264 

1.256 

1.249 

.243 

1.236 

1.229 

1.222 

1.215 

1.209 

20 

1.202 

.196 

1.189 

1.183 

.177 

1.171 

1.164 

1.158 

1.152 

1.146 

21 

1.140 

.134 

1.129 

1.123 

.117 

1.111 

1.106 

1.100 

1.095 

1.089 

22 

1.084 

1.079 

1.073 

1.068 

.063 

1.058 

1.053 

1.047 

1.042 

1.037 

23 

1.033 

1.028 

1.023 

1.018 

1.013 

1.008 

1.004 

0.999 

0.994 

0.990 

24 

0.985 

0.981 

0.976 

0.972 

0.968 

0.963 

0.959 

0.955 

0.950 

0.946 

25 

0.942 

0.938 

0.934 

0.930 

0.926 

0.922 

0.918 

0.914 

0.910 

0.006 

26 

0.902 

0.898 

0.894 

0.891 

0.887 

0.883 

0.879 

0.876 

0.872 

0.869 

27 

0.865 

0.861 

0.858 

0.854 

0.851 

0.847 

0.844 

0.841 

0.837 

0.834 

28 

0.831 

VI. 

ESTIMATION   OF  PERCENTAGE    OF  SUGAR    BY   WEIGHT 
IN  WEAK  SUGAR  SOLUTIONS 

Tucker:  Manual  of  Sugar  Analysis. 

Abridged  from  a  table  calculated  by 

OSWALD. 


260 


SUGAR  ANALYSIS 


VI. 


IN- 

oS 

|| 

'u  > 

Is 

OQO 

READING  OF  THE  SACCHARIMETER. 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

0.0 

1.0000 

.260 

.521 

.781 

1.042 

1.302 

1.563 

1.823 

2.084 

2.344 

2.605 

0.5 

1.0019 

.260 

.520 

.780 

1.040 

1.300 

1.560 

1.820 

2.080 

2.340 

2.600 

1.0 

1.0039 

.259 

.519 

.778 

1.038 

1.297 

1.557 

1.816 

2.076 

2.335 

2.595 

1.5 

1.0058 

.259 

.518 

.777 

1.036 

1.295 

1.554 

1.813 

2.072 

2.331 

2.590 

2.0 

1.0078 

.258 

.517 

.775 

1.034 

1.292 

1.551 

1.809 

2.068 

2.326 

2.585 

2.5 

1.0097 

.258 

.516 

.774 

1.032 

1.290 

1.548 

1.806 

2.064 

2.322 

2.580 

3.0 

1.0117 

.257 

.515 

.772 

1.029 

1.287 

1.545 

1.802 

2.060 

2.317 

2.575 

3.5 

1.0137 

.257 

.514 

.771 

1.028 

1.285 

1.542 

1.799 

2.056 

2.313 

2.570 

4.0 

1.0157 

.256 

.513 

.769 

1.026 

1.282 

1.539 

1.795 

2.052 

2.308 

2.565 

4.5 

1.0177 

.256 

.512 

.768 

1.024 

1.280 

.536 

1.792 

2.048 

2.304 

2.559 

5.0 

1.0197 

.255 

.511 

.766 

1.022 

1.277 

.533 

1.788 

2.044 

2.299 

2.554 

5.5 

.0213 

.255 

.510 

.765 

1.020 

1.275 

.530 

1.785 

2.040 

2.295 

2.549 

6.0 

.0237 

.254 

.509 

.763 

1.018 

1.272 

.527 

1.781 

2.036 

2.290|2.544 

6.5 

.0257 

.254 

.508 

.762 

1.016 

1.270 

.524 

1.778 

2.032 

2.285 

2.539 

7.0 

.0278 

.253 

.507 

.760 

1.014 

1.267 

1.521 

1.774 

2.027 

2.281 

2.534 

7.5 

.0298 

.253 

.506 

.758 

1.012 

.265 

1.518 

1.771 

2.023 

2.276 

2.529 

8.0 

.0319 

.252 

.505 

.757 

1.010 

.262 

1.515 

1.767 

2.019 

2.272 

2.524 

8.5 

.0339 

.252 

.504 

.756 

1.008 

.260 

1.512 

1.763 

2.015 

2.267 

2.519 

9.0 

1.0360 

.251 

.503 

.754 

1.006 

.257 

1.509 

1.760 

2.011 

2.263 

2.514 

9.5 

1.0380 

.251 

.502 

.753 

1.004 

.255 

1.506 

1.757 

2.007 

2.258 

2.509 

10.0 

1.0410 

.250 

.501 

.751 

1.002 

.252 

1.503 

1.753 

2.003 

2.254 

2.504 

10.5 

1.0422 

.250 

.500 

.750 

1.000 

.250 

1.500 

1.750 

1.999 

2.249 

2.499 

11.0 

1.0443 

.249 

.499 

.748 

.998 

.247 

1.497 

1.746 

1.995 

2.245 

2.494 

11.5 

1.0464 

.249 

.498 

.747 

.996 

.245 

1.494 

1.743 

.991 

2.240 

2.489 

12.0 

1  .0485 

.248 

.497 

.745 

.994 

.242 

1.491 

1.739 

.987 

2.236 

2.484 

12.5 

1.0506 

.248 

.496 

.744 

.992 

.240 

1.488 

1.735 

.983 

2.231 

2.479 

13.0 

1.0528 

.247 

.495 

.742 

.990 

.237 

1.484 

1.732 

.979 

2.227 

2.474 

13.5 

1.0549 

.247 

.494 

.741 

.988 

.235 

1.482 

1.728 

.975 

2.222 

2.469 

14.0 

1.0570 

.246 

.493 

.739 

.986 

.232 

1.479 

1.725 

1.971 

2.218 

2.464 

14.5 

1.0591 

.246 

.492 

.738 

.984 

.230 

1.476 

1.722 

1.967 

2.213 

2.459 

15.0 

1.0613 

.245 

.491 

.736 

.982 

.227 

1.473 

1.718 

1.963 

2.209 

2.454 

15.5 

1.0635 

.245 

.490 

.735 

.980 

.225 

1.470 

1.714 

1.959 

2.204 

2.449 

16.0 

1.0657 

.244 

.489 

.733 

.978 

.222 

1.467 

1.711 

1.955 

2.200 

2.444 

16.5 

1.0678 

.244 

.488 

.732 

.976 

1.220 

1.464 

1.708 

1.951 

2.195 

2.439 

17.0 

1.0700 

.243 

.487 

.730 

.974 

1.217 

1.461 

1.704 

1.948 

2.191 

2.434 

17.5 

1.0722 

.243 

.486 

.729 

.972 

1.215 

1.458 

1.701 

1.944 

2.186 

2.429 

18.0 

1.0744 

.242 

.485 

.727 

.970 

1.212 

1.455 

1.697 

1.940 

2.182 

2.424 

18.5 

1.0765 

.242 

.484 

.726 

.968 

1.210 

1.452 

1.694 

1.936 

2.178 

2.420 

19.0 

1.0787 

.241 

.483 

.724 

.966 

1.207 

1.449 

1.690 

1.932 

2.173 

2.415 

19.5 

1.0810 

.241 

.482 

.723 

.964 

1.205 

.446 

1.687 

1.928 

2.169 

2.410 

20.0 

1.0833 

.240 

.481 

.721 

.962 

1.202 

.443 

1.683 

1.924 

2.164 

2.405 

20.5 

1.0855 

.240 

.480 

.720 

.960 

1.200 

.440 

1.680 

1.920 

2.160 

2.400 

21.0 

1.0878 

.239 

.479 

.718 

.958 

1.197 

.437 

1.676 

1.916 

2.155 

2.395 

21.5 

1.0900 

.239 

.478 

.717 

.956 

1.195 

.434 

1.673 

1.912 

2.151 

2.390 

22.0 

1.0923 

.238 

.477 

.715 

.954 

1.192 

.431 

1.669 

1.908 

2.146 

2.385 

22.5 

1.0946 

.238 

.476 

.714 

.952 

1.190 

1.428 

1.666 

1.904 

2.142 

2.380 

23.0 

1.0969 

.237 

.475 

.712 

.950 

1.187 

1.425 

1.662 

1.900 

2.137 

2.375 

VII. 

•HUNDRED  POLARIZATION" 
(SCHEIBLER.) 


262 


SUGAR  ANALYSIS 


VII. 


Instead  of  13.024  g. 

Instead  of  13.024  g. 

Instead  of  13.024  g. 

there  must  be  taken 

there  must  be  taken 

there  must  be  taken 

o  • 

I-j 

"73 

Q* 

Grams. 

Differ- 
ence. 

o>"O 

Grams. 

Differ- 
ence. 

jh 

Grams. 

Differ- 
ence. 

82.0 

15.883 

2.859 

86.0 

15  .  144 

2.120 

90.0 

14.471 

1.447 

1 

864 

840 

1 

127 

103 

1 

455 

431 

2 

844 

820 

2 

109 

085 

2 

439 

415 

3 

825 

801 

3 

092 

068 

3 

423 

399 

4 

806 

782 

4 

074 

050 

4 

407 

383 

5 

778 

763 

5 

057 

033 

5 

391 

367 

6 

768 

744 

6 

039 

015 

6 

375 

351 

7 

748 

724 

7 

022 

1.998 

7 

359 

335 

8 

729 

705 

8 

005 

981 

8 

344 

320 

9 

710 

686 

9 

14.987 

963 

9 

328 

304 

83.0 

692 

668 

87.0 

970 

946 

91.0 

312 

288 

1 

673 

649 

1 

953 

929 

1 

296 

272 

2 

654 

630 

2 

936 

912 

2 

281 

257 

3 

635 

611 

3 

919 

895 

3 

265 

241 

4 

616 

592 

4 

902 

878 

4 

249 

225 

5 

598 

574 

5 

885 

861 

5 

234 

210 

6 

579 

555 

6 

868 

844 

6 

218 

194 

7 

560 

536 

7 

851 

827 

7 

203 

179 

8 

542 

518 

8 

834 

810 

8 

187 

163 

9 

523 

499 

9 

817 

793 

9 

172 

148 

84.0 

505 

481 

88.0 

800 

776 

92.0 

157 

133 

1 

486 

462 

1 

783 

759 

1 

141 

117 

2 

468 

444 

2 

766 

742 

2 

126 

102 

3 

450 

426 

3 

750 

726 

3 

111 

087 

4 

431 

407 

4 

733 

709 

4 

095 

071 

5 

413 

389 

5 

717 

693 

5 

080 

056 

6 

395 

371 

6 

700 

676 

6 

065 

041 

7 

377 

353 

7 

683 

659 

7 

050 

026 

8 

358 

334 

8 

667 

643 

8 

034 

010 

9 

340 

316 

9 

650 

626 

9 

019 

0.995 

85.0 

322 

298 

89.0 

634 

610 

93.0 

004 

980 

1 

304 

280 

1 

617 

593 

1 

13.989 

965 

2 

286 

262 

2 

601 

577 

2 

974 

950 

3 

268 

244 

3 

585 

561 

3 

959 

935 

4 

251 

227 

4 

568 

544 

4 

944 

920 

5 

233 

209 

5 

552 

528 

5 

929 

905 

6 

215 

191 

6 

536 

512 

6 

915 

891 

7 

197 

173 

7 

520 

496 

7 

900 

876 

8 

179 

155 

8 

503 

479 

8 

885 

861 

9 

162 

138 

9 

487 

463 

9 

870 

846 

TABLES 


263 


VII. 


i 

». 

Instead  of  13.024  g. 
there  must  be  taken 

i 

Instead  of  13.024  g. 
there  must  be  taken 

i-d 

Instead  of  13.024  g. 
there  must  be  taken 

hr  "^ 

Q  * 

Grams. 

Differ- 
ence. 

&2 

Grams. 

Differ- 
ence. 

Grams. 

Differ- 
ence. 

94.0 

13.855 

0.831 

96.0 

13.567 

0.543 

98.0 

13.290 

0.266 

1 

841 

817 

1 

553 

529 

1 

276 

252 

2 

826 

802 

2 

538 

514 

2 

263 

239 

3 

811 

787 

3 

524 

500 

3 

249 

225 

4 

797 

773 

4 

510 

486 

4 

236 

212 

5 

782 

758 

5 

496 

472 

5 

222 

198 

6 

767 

743 

6 

482 

458 

6 

209 

185 

7 

753 

729 

7 

468 

444 

7 

196 

172 

8 

738 

714 

8 

455 

431 

8 

182 

158 

9 

724 

700 

9 

441 

417 

9 

169 

145 

95.0 

710 

686 

97.0 

427 

403 

99.0 

156 

132 

1 

695 

671 

1 

413 

389 

1 

142 

118 

2 

681 

657 

2 

399 

375 

2 

129 

105 

3 

666 

642 

3 

385 

361 

3 

116 

092 

4 

652 

628 

4 

372 

348 

4 

103 

079 

5 

638 

614 

5 

358 

334 

5 

089 

065 

6 

623 

599 

6 

344 

320 

6 

076 

052 

7 

609 

585 

7 

331 

307 

7' 

063 

039 

8 

595 

571 

8 

317 

293 

8 

050 

026 

9 

581 

557 

9 

303 

279 

9 

037 

013 

100.0 

024 

000 

VIII. 
ESTIMATION  OF  PERCENTAGE  OF  SUGAR  BY   WEIGHT: 

FOR  USE  WITH  SOLUTIONS  PREPARED  BY  ADDITION  OF  1/10  VOLUME 
BASIC  ACETATE  OF  LEAD. 

For  Soleil-Ventzke  Polariscopes. 
SCHMITZ. 


266 


SUGAR  ANALYSIS 


VIII. 


PER  CENT  BRIX 
vor\\jt  n  f\  rrn  1  9  D 

a 

PER  CENT  BRIX  AND 

FROM    U.O    TO    l^.U 

oS 

Tenths 
of  a 
Degree. 

Per  Cent 
Sucrose 

£2 

V 

0.5 

1.0019 

1.0 

1.0039 

1.5 

1.0058 

2.0 
1.0078 

2.5 

1.0098 

3.0 

,1.0117 

3.5 
1.0137 

4.0 
1.0157 

4.5 

1.0177 

0.1 

0.03 

i 

0.29 

0.29 

0.29 

0.28 

0.28 

0.28 

0.28 

0.28 

0.28 

0.2 

0.06 

2 

0.57 

0.57 

0.57 

0.57 

0.56 

0.56 

0.56 

0.56 

0.3 

0.08 

3 

0.85 

0.85 

0.85 

0.85 

0.85 

0.85 

0.84 

0.84 

0.4 

0.11 

4 

1.14 

1.13 

1.13 

1.13 

1.13 

1.13 

1.12 

0.5 

0.14 

5 

1.42 

1.42 

1.41 

1.41 

1.41 

1.41 

1.40 

0.6 

0.17 

6 

1.70 

1.70 

1.69 

1.69 

1.69 

1.68 

0.7 

0.19 

7 

1.98 

1.98 

1.98 

1.97 

1.97 

1.96 

0.8 

0.22 

8 

2.26 

2.26 

2.26 

2.25 

2.25 

0.9 

0.25 

9 

2.54 

2.54 

2.53 

2.53 

10 

2.82 

2.82 

2.81 

2.81 

11 

3.10 

3.09 

3.09 

12 

3.38 

3.38 

3.37 

13 

3.6f 

3.65 

14 

3.94 

3.93 

PER  CENT  BRIX 

15 

4.21 

FROM   12.5  TO  20.0 

16 

4.49 

17 

Tenths 
of  a 
Degree. 

Per  Cent 
Sucrose. 

18 
19 

20 

0.1 

0.03 

21 

0.2 

0.05 

22 

0.3 

0.08 

23 

0.4 

0.11 

24 

0.5 

0.13 

25 

0.6 

0.16 

26 

0.7 

0.19 

27 

0.8 

0.21 

28 

0.9 

0.24 

29 

30 

31 

32 

33 

34 

35 

36 

37 

•  Q 

oo 
39 

TABLES 


267 


VIII 


CORRESPONDING  SPECIFIC  GRAVITY. 

• 

5.0 

5.5 

6.0 

6.5 

7.0 

7.5 

8.0 

8.5 

9.0 

9.5 

10.0 

03  0? 

1.0197 

1.0217 

1.0237 

1.0258 

1.0278 

1.0298 

1.0319 

1.0339 

1.0360 

1.0381 

1.040 

1° 

0.28 

0.28 

0.28 

0.28 

0.28 

0.28 

0.28 

0.28 

0.28 

0.28 

0.2 

1 

0.56 

0.56 

0.56 

0.56 

0.56 

0.55 

0.55 

0.55 

0.55 

0.55 

0.55 

2 

0.84 

0.84 

0.84 

0.84 

0.83 

0.83 

0.83 

0.83 

0.83 

0.83 

0.82 

3 

1.12 

1.12 

1.12 

1.11 

1.11 

1.11 

1.11 

1.11 

1.10 

1.1C 

1.10 

4 

1.40 

1.40 

1.40 

1.39 

1.39 

1.39 

1.38 

1.38 

l.%38 

1.38 

1.37 

5 

1.68 

1.68 

1.67 

1.67 

1.67 

1.66 

1.66 

1.66 

1.66 

1.65 

1.65 

6 

1.96 

1.96 

1.95 

1.95 

1.95 

1.94 

1.94 

1.93 

1.93 

1.93 

1.92 

7 

2.24 

2  24 

2.23 

2,23 

2.22 

2.22 

2.22 

2  21 

2.21 

2.20 

2.20 

8 

2.52 

2^52 

2.51 

2.51 

2.50 

2.50 

2^49 

2^49 

2.48 

2.48 

2.47 

9 

2.80 

2.80 

2.79 

2.79 

2.78 

2.78 

2.77 

2.76 

2.76 

2.75 

2.75 

10 

3.08 

3.08 

3.07 

3.06 

3.06 

3.05 

3.05 

3.04 

3.03 

3.03 

3.02 

11 

3.36 

3.36 

3.35 

3.34 

3.34 

3.33 

3.32 

3.32 

3.31 

3.30 

3.30 

12 

3.64 

3.64 

3.63 

3.62 

3.61 

3.61 

3.60 

3.59 

3.59 

3.58 

3.57 

13 

3.92 

3.92 

3.91 

3.90 

3.89 

3.88 

3.88 

3.87 

3.86 

3.85 

3.85 

14 

4.20 

4.19 

4.19 

4.18 

4.17 

4.16 

4.15 

4.15 

4.14 

4.13 

4.12 

15 

4.48 

4.47 

4.47 

4.46 

4.45 

4.44 

4.43 

4.42 

4.41 

4.40 

4.40 

16 

4.77 

4.76 

4.75 

4.74 

4.73 

4.72 

4.71 

4.70 

4.69 

4.68 

4.67 

17 

5.03 

5.02 

5.01 

5.00 

4.99 

4.99 

4.97 

4.97 

4.96 

4.95 

18 

5.32 

5.31 

5.29 

5.28 

5.27 

5.26 

5.25 

5.24 

5.23 

5.22 

19 

5.58 

5.57 

5.56 

5.55 

5.54 

5.53 

5.52 

5.51 

5.50 

20 

5.86 

5.85 

5.84 

5.83 

5.82 

5.81 

5.79 

5.78 

5.77 

21 

6.13 

6.12 

6.11 

6.09 

6.08 

6.07 

6.06 

6.05 

22 

6.41 

6.40 

6.38 

6.37 

6.36 

6.35 

6.33 

6.32 

23 

6.67 

6.66 

6.65 

6.64 

6.62 

6.61 

6.60 

24 

6.94 

6.93 

6.91 

6.90 

6.89 

6.87 

25 

7.22 

7.20 

7.19 

7.17 

7.16 

7.15 

26 

7.48 

7.46 

7.45 

7.44 

7.42 

27 

7.76 

7.74 

7.73 

7.71 

7.70 

28 

8.02 

8.00 

7.99 

7.97 

29 

8.28 

8.26 

8.25 

30 

8.55 

8.54 

8.52 

31 

8.83 

8.81 

8.80 

32 

9.09 

9.07 

33 

9.35 

34 

9.62 

35 

36 

37 

38 

39 

268 


SUGAR  ANALYSIS 


VIII. 


PER  CENT  BRIX 

PER  CENT  BRIX  AND 

FROM  0.5  TO   12.0 

h 

O  0> 

T*    & 

10.5 

11.0 

11.5 

12.0 

12.5 

13.0 

13.5 

14.0 

14.5 

Tenths 

Per  Cen 

«  ° 

of  a 

Sucrose 

oC 

1.0422 

1.0443 

1.0464 

1.0485 

1.0506 

1.0528 

1.0549 

1.0570 

1.0592 

Degree. 

__ 

0.1 

0.03 

1 

0.28 

0.27 

0.27 

0.27 

0.27 

0.27 

0.27 

0.27 

0.27 

0.2 

0.06 

2 

0.55 

0.55 

0.55 

0.55 

0.54 

0.54 

0.54 

0.54 

0.54 

0.3 

0.08 

3 

0.82 

0.82 

0.82 

0.82 

0.82 

0.81 

0.81 

0.81 

0.81 

0.4 

0.11 

4 

1.10 

1.10 

1.09 

1.09 

1.09 

1.09 

1.08 

1.08 

1.08 

0.5 

0.14 

5 

1.37 

1.37 

1.36 

1.36 

1.36 

1.36 

1.35 

1.35 

1.35 

0.6 

0.17 

6 

1.64 

1.64 

1.64 

1.64 

1.63 

1.63 

1.62 

1.62 

1.62 

0.7 

0.19 

7 

1.92 

1.91 

1.91 

1.91 

1.90 

1.9C 

1.89 

1.89 

1.89 

0.8 

0.22 

8 

2.19 

2.19 

2.18 

2.18 

2.18 

2.17 

2.17 

2.16 

2.16 

0.9 

0.25 

9 

2.47 

2.46 

2.46 

2.45 

2.45 

2.44 

2.44 

2.43 

2.43 

10 

2.74 

2.74 

2.73 

2.73 

2.72 

2.71 

2.71 

2.70 

2.70 

11 

3.02 

3.01 

3.00 

3.00 

2.99 

2.99 

2.98 

2.97 

2.97 

12 

3.29 

3.28 

3.28 

3.27 

3.26 

3.26 

3.25 

3.24 

3.24 

13 

3.56 

3.56 

3.55 

3.54 

3.54 

3.53 

3.52 

3.51 

3.51 

14 

3.84 

3.83 

3.82 

3.82 

3.81 

3.80 

3.79 

3.78 

3.78 

PER  CENT  BRIX 

FROM  12.5  TO  20.0. 

15 
16 

4.11 
4.39 

4.11 
4.38 

4.10 
4.37 

4.09 
4.36 

4.08 
4.35 

4.07 
4.34 

4.06 
4.33 

4.06 
4.33 

4.05 
4.32 

17 

4.66 

4.65 

4.64 

4.63 

4.62 

4.62 

4.61 

4.60 

4.59 

Tenths 
of  a 

Per  Cent 

18 

4.93 

4.93 

4.91 

4.91 

4.90 

4.89 

4.88 

4.87 

4.86 

Degree. 

Sucrose. 

19 

5.21 

5.20 

5.19 

5.18 

5.17 

5.16 

5.15 

5.14 

5.13 

20 

5.49 

5.47 

5.46 

5.45 

5.44 

5.43 

5.42 

5.41 

5.40 

0.1 

0.03 

21 

5.76 

5.75 

5.74 

5.73 

5.71 

5.70 

5.69 

5.68 

5.67 

0.2 

0.05 

22 

6.03 

6.02 

6.01 

6.00 

5.99 

5.97 

5.96 

5.95 

5.94 

0.3 

0.08 

23 

6.31 

6.30 

6.28 

6.27 

6.26 

6.24 

6.23 

6.22 

6.21 

0.4 

0.11 

24 

6.58 

6.57 

6.56 

6.54 

6.53 

6.52 

6.50 

6.49 

6.48 

0.5 

0.13 

25 

6.86 

6.84 

6.83 

6.82 

6.80 

6.79 

6.78 

6.76 

6.75 

0.6 

0.16 

26 

7.13 

7.12 

7.10 

7.09 

7.07 

7.06 

7.05 

7.03 

7.02 

0.7 

0.19 

27 

7.41 

7.39 

•7.38 

7.36 

7.35 

7.33 

7.32 

7.30 

7.29 

0.8 

0.21 

28 

7.68 

7.66 

7.65 

7.63 

7.62 

7.60 

7.59 

7.57 

7.56 

0.9 

0.24 

29 

7.96 

7.94 

7.92 

7.91 

7.89 

7.87 

7.86 

7.84 

7.83 

30 

8.23 

8.21 

8.20 

8.18 

8.16 

8.15 

8.13 

8.11 

8.10 

31 

8.50 

8.49 

8.47 

8.45 

8.44 

8.42 

8.40 

8.39 

8.37 

32 

8.78 

8.76 

8.74 

8.73 

8.71 

8.69 

8.67 

8.66 

8.64 

33 

9.05 

9.03 

9.02 

9.00 

8.98 

8.96 

8.94 

8.93 

8.91 

34 

9.33 

9.31 

9.29 

9.27 

9.25 

9.23 

9.22 

9.20 

9.18 

35 

9.60 

9.58 

9.56 

9.54 

9.53 

9.51 

9.49 

9.47 

9.45 

36 

9.88 

9.86 

9.84 

9.82 

9.80 

9.78 

9.76 

9.74 

9.72 

37 

10.15 

0.13 

10.11 

10.09 

10.07 

0.05 

10.03 

10.01 

9.99 

38 

0.40 

10.38 

10.36 

10.34 

0.32 

10.30 

10.28 

10.26 

39 

0.68 

10.66 

10.64 

10.61 

0.5910.57 

10.55 

10.53 

TABLES 


269 


VIII. 


CORRESPONDING  SPECIFIC  GRAVITY. 

15.0 

15.5 

16.0 

16.5 

17.0 

17.5 

18.0 

18.5 

19.0 

19.5 

20.0 

a  • 

O  flS 

'E  & 

1.0613 

1.0635 

1.0657 

1.0678 

1.0700 

1.0722 

1.0744 

1.0766 

1.0788 

1.0811 

1.0833 

¥ 

0.27 

0.27 

0.27 

0.27 

0.27 

0.27 

0.27 

0.27 

0.27 

0.27 

0.26 

i 

0.54 

0.54 

0.54 

0.54 

0.53 

0.53 

0.53 

0.53 

0.53 

0.53 

0.53 

2 

0.81 

0.81 

0.80 

0.80 

0.80 

0.80 

0.80 

0.80 

0.79 

0.79 

0.79 

3 

1.08 

1.08 

1.07 

1.07 

1.07 

1.07 

1.06 

1.06 

1.06 

1.06 

1.06 

4 

1.35 

1.34 

1.34 

1.34 

1.34 

1.33 

1.33 

1.33 

1.32 

1.32 

1.32 

5 

1.62 

1.61 

1.61 

1.61 

1.60 

1.60 

1.60 

1.59 

1.59 

1.59 

1.58 

6 

1.88 

1.88 

1.88 

1.87 

1.87 

1.86 

1.86 

1.86 

1.85 

1.85 

1.85 

7 

2.15 

2.15 

2.15 

2.14 

2.14 

2.13 

2.13 

2.12 

2.12 

2.12 

2.11 

8 

2.42 

2.42 

2.41 

2.41 

2.40 

2.40 

2.39 

2.39 

2.38 

2.38 

2.37 

9 

2.69 

2.69 

2.68 

2.68 

2.67 

2.67 

2.66 

2.65 

2.65 

2.64 

2.64 

10 

2.96 

2.95 

2.95 

2.94 

2.94 

2.93 

2.92 

2.92 

2.91 

2.91 

2.90 

11 

3.23 

3.22 

3.22 

3.21 

3.20 

3.20 

3.19 

3.18 

3.18 

3.17 

3.17 

12 

3.50 

3.49 

3.49 

3.48 

3.47 

3.46 

3.46 

3.45 

3.44 

3.44 

3.43 

13 

3.77 

3.76 

3.75 

3.75 

3.74 

3.73 

3.72 

3.72 

3.71 

3.70 

3.69 

14 

4.04 

4.03 

4.02 

4.02 

4.01 

4.00 

3.99 

3.98 

3.97 

3.97 

3.96 

15 

4.31 

4.30 

4.29 

4.28 

4.27 

4.26 

4.26 

4.25 

4.24 

4.23 

4.22 

16 

4.58 

4.57 

4.56 

4.55 

4.54 

4.53 

4.52 

4.51 

4.50 

4.49 

4.48 

17 

4.85 

4.84 

4.83 

4.82 

4.81 

4.80 

4.79 

4.78 

4.77 

4.76 

4.75 

18 

5.12 

5.11 

5.10 

5.09 

5.08 

5.06 

5.05 

5.04 

5.03 

5.02 

5.01 

19 

5.39 

5.38 

5.36 

5.35 

5.34 

5.33 

5.32 

5.31 

5.30 

5.29 

5.28 

20 

5.66 

5.65 

5.63 

5.62 

5.61 

5.60 

5.59 

5.58 

5.56 

5.55 

5.54 

21 

5.93 

5.91 

5.90 

5.89 

5.88 

5.87 

5.85 

5.84 

5.83 

5.82 

5.80 

22 

6.20 

6.18 

6.17 

6.16 

6.14 

6.13 

6.12 

6.11 

6.09 

6.08 

6.07 

23 

6.46 

6.45 

6.44 

6.43 

6.41 

6.40 

6.39 

6.37 

6.36 

6.35 

6.33 

24 

6.73 

6.72 

6.71 

6.69 

6.68 

6.67 

6.65 

6.64 

6.63 

6.61 

6.60 

25 

7.00 

6.99 

6.97 

6.96 

6.95 

6.93 

6.92 

6.90 

6.89 

6.88 

6.86 

26 

7.27 

7.26 

7.24 

7.23 

7.21 

7.20 

7.18 

7.17 

7.15 

7.14 

7.13 

27 

7.54 

7.53 

7.51 

7.50 

7.48 

7.47 

7.45 

7.44 

7.42 

7.40 

7.39 

28 

7.81 

7.80 

7.78 

7.77 

7.75 

7.73 

7.72 

7.70 

7.68 

7.67 

7.65 

29 

8.08 

8.06 

8.05 

8.03 

8.02 

8.00 

7.98 

7.97 

7.95 

7.93 

7.92 

30 

8.35 

8.33 

8.32 

8.30 

8.28 

8.27 

8.25 

8.23 

8.21 

8.20 

8.18 

31 

8.62 

8.60 

8.58 

8.57 

8.55 

8.53 

8.51 

8.50 

8.48 

8.46 

8.45 

32 

8.89 

8.87 

8.85 

8.84 

8.82 

8.80 

8.78 

8.76 

8.75 

8.73 

8.71 

33 

9.16 

9.14 

9.12 

9.10 

9.09 

9.07 

9.05 

9.03 

9.01 

8.99 

8.97 

34 

9.43 

9.41 

9.39 

9.37 

9.35 

9.34 

9.31 

9.30 

9.28 

9.26 

9.24 

35 

9.70 

9.68 

9.66 

9.64 

9,.  62 

9.60 

9.58 

9.56 

9.54 

9.52 

9.50 

36 

9.97 

9.95 

9.93 

9.91 

9.89 

9.87 

9.85 

9.83 

9.81 

9.79 

9.77 

37 

10.24 

10.22 

10.20 

10.18 

10.15 

10.13 

0.11 

10.09 

10.07 

0.05 

0.03 

38 

10.51 

10.49 

10.46 

10.44 

10.42 

0.40 

0.38 

10.36 

10.34 

0.32 

0.29 

39 

270 


SUGAR  ANALYSIS 


VIII. 


PER  CENT  BRIX 

PER  CENT  BRIX  AND 

FROM  115  TO  22  5 

2  . 

Polariscoj 
Degrees 

11.5 

1.0464 

12.0 
1.0485 

12.5 
1.0506 

13.0 
1.0528 

13.5 
1.0549 

14.0 
1.0570 

Tenths 
of  a 
Degree. 

Per  Cen 
Sucrose 

40 

10.93 

10.91 

10.89 

10.86 

10.84 

10.82 

0.1 

0.03 

41 

11.18 

11.16 

11.14 

11.12 

11.09 

0.2 

0.05 

42 

11.46 

11.43 

11.41 

11.39 

11.36 

0.3 

0.08 

43 

11.71 

11.68 

11.66 

11.64 

0.4 

0.11 

44 

11.98 

11.95 

11.93 

11.91 

0.5 

0.13 

45 

12.25 

12.23 

12.20 

12.18 

0.6 

0.16 

46 

12.50 

12.47 

12.45 

0.7 

0.19 

47 

12.74 

12.72 

0.8 

0.21 

48 

13.02 

12.99 

0.9 

0.24 

49 

13.26 

50 

51 

52 

53 

54 

PER  CENT  BRIX 

55 

FROM  23.0  TO  24.0 

56. 

57 

Tenths 
of  a 
Degree. 

Per  Cent 
Sucrose 

58 
59 

60 

0.1 

0.03 

61 

0.2 

0.05 

62 

0.3 

0.08 

63 

0.4 

0.10 

64 

0.5 

0.13 

65 

0.6 

0.16 

66 

0.7 

0.18 

67 

0.8 

0.21 

68 

0.9 

0.23 

69 

70 

71 

72 

73 

74 

75 

76 

77 

78 

79 

80 

TABLES 


271 


VIII. 


CORRESPONDING  SPECIFIC  GRAVITY. 

s,  • 

14.5 

15.0 

15.5 

16.0 

16.5 

17.0 

17.5 

II 

1.0592 

1.0613 

1.0635 

1.0657 

1.0678 

1.0700 

1.0722 

11 

AH 

10.80 

10.78 

10.76 

10.73 

10.71 

10.69 

10.67 

40 

11.07 

11.05 

11.03 

11.00 

10.98 

10.96 

10.94 

41 

11.34 

11.32 

11.29 

11.27 

11.25 

11.23 

11.20 

42 

11.61 

11.59 

11.56 

11.54 

11.52 

11.49 

11.47 

43 

11.88 

11.86 

11.83 

11.81 

11.79 

11.76 

11.74 

44 

12.15 

12.13 

12.10 

12.08 

12.05 

12.03 

12.01 

45 

12.42 

12.40 

12.37 

12.35 

12.32 

12.30 

12.27 

46 

12.69 

12.67 

12.64 

12.61 

12.59 

12.56 

12.54 

47 

12.97 

12.94 

12.91 

12.88 

12.86 

12.83 

12.81 

48 

13.23 

13.21 

13.18 

13.15 

13.13 

13.10 

13.07 

49 

13.50 

13.48 

13.45 

13.42 

13.40 

13.37 

13.34 

50 

13.78 

13.75 

13.72 

13.69 

13.66 

13.64 

13.61 

51 

14.02 

13.99 

13.96 

13.93 

13.90 

13.88 

52 

14.29 

14.26 

14.23 

14.20 

14.17 

14.14 

53 

14.53 

14.50 

14.47 

14.44 

14.41 

54 

14.80 

14.77 

14.74 

14.71 

14.68 

55 

15.03 

15.00 

14.97 

14.94 

56 

15.30 

15.27 

15.24 

15.21 

57 

15.57 

15.54 

15.51 

15.48 

58 

15.81 

15.78 

15.75 

59 

16.05 

16.01 

60 

16.31 

16.28 

61 

16.55 

62 

16.82 

63 

64 

65 

66 

67 

ao 

Do 

69 

70 

71 

72 

73 

74 

75 

76 

> 

77 

78 

79 

80 

272 


SUGAR  ANALYSIS 


VIII. 


PER  CENT  BRIX 

FROM   115  TO  22  < 

o> 
ft   . 

PER  CENT  BRIX  AND 

II 

£  W) 
03  0) 

18.0 

18.5 

19.0 

19.5 

20.0 

20.5 

Tenths 

Per  cent 

of  a 
degree. 

Sucrose. 

"oQ 

AH 

1.0744 

1.0766 

1.0788 

1.0811 

1.0833 

1.0855 

40 

10.64 

10.62 

10.60 

10.58 

10.56 

10.54 

0.1 

0.03 

41 

10.91 

10.89 

10.87 

10.85 

10.82 

10.80 

0.2 

0.05 

42 

11.18 

11.16 

11.13 

11.11 

11.09 

11.07 

0.3 

0.08 

43 

11.45 

11.42 

11.40 

11.38 

11.35 

11.33 

0.4 

0.11 

44 

11.71 

11.69 

31.66 

11.64 

11.62 

11.59 

0.5 

0.13 

45 

11.98 

11.96 

11.93 

11.91 

11.88 

11.86 

0.6 

0.16 

46 

12.25 

12.22 

12.20 

12.17 

12.15 

12.12 

0.7 

0.19 

47 

12.51 

12.49 

12.46 

12.44 

12.41 

12.39 

0.8 

0.21 

48 

12.78 

12.75 

12.73 

12.70 

12.67 

12.65 

0.9 

0.24 

49 

13.05 

13.02 

12.99 

12.97 

12.94 

12.91 

50 

13.31 

13.29 

13.26 

13.23 

13.20 

13.18 

51 

13.58 

13.55 

13.52 

13.50 

13.47 

13.44 

52 

13.85 

13.82 

13.79 

13.76 

13.73 

13.70 

53 

14.11 

14.08 

14.05 

14.03 

14.00 

13.97 

54 

14.38 

14.35 

14.32 

14.29 

14.26 

14.23 

PER  CENT  BRIX 

FROM  23.0  TO  24.0 

55 
56 

14.65 
14.91 

14.62 

14.88 

14.59 
14.85 

14.56 

14.82 

14.53 
14.79 

14.50 
14.76 

57 

15.18 

15.15 

15.12 

15.09 

15.06 

15.02 

Tenths 
of  a 
degree. 

Per  cent 
Sucrose. 

58 
59 

15.45 
15.71 

15.42 
15.68 

15.38 
15.65 

15.35 
15.62 

15.32 

15.58 

15.29 
15.55 

60 

15.98 

15.95 

15.92 

15.88 

15.85 

15.82 

0.1 

0.03 

61 

16.25 

16.21 

16.18 

16.15 

16.11 

16.08 

0.2 

0.05 

62 

16.52 

16.48 

16.45 

16.41 

16.38 

16.35 

0.3 

0.08 

63 

16.78 

16.75 

16.71 

16.68 

16.64 

16.61 

0.4 

0.10 

64 

17.05 

17.01 

16.98 

16.94 

16.91 

16.87 

0.5 

0.13 

65 

17.32 

17.28 

17.24 

17.21 

17.17 

17.14 

0.6 

0.16 

66 

17.55 

17.51 

17.47 

17.44 

17.40 

0.7 

0.18 

67 

17.81 

17.78 

17.74 

17.70 

17.67 

0.8 

0.21 

68 

18.04 

18.00 

17.97 

17.93 

0.9 

0.23 

69 

18.31 

18.27 

18.23 

18.19 

70 

18.53 

18.50 

18.46 

71 

18.76 

18.72 

72 

19.03 

18.99 

73 

19.25 

74 

19.52 

75 

19.78 

76 

77 

1 

78 

79 

80 

TABLES 


273 


VIII. 


CORRESPONDING  SPECIFIC  GRAVITY. 

&  • 

21.0 

21.5 

22.0 

22.5 

23.0 

23.5 

24.0 

O  42 

1.0878 

1.0900 

1.0923 

1.0946 

1.0969 

1.0992 

1.1015 

z& 

10.52 

10.49 

10.47 

10.45 

10.43 

10.41 

10.38 

40 

10.78 

10.76 

10.74 

10.71 

10.69 

10.67 

10.65 

41 

11.04 

11.02 

11.00 

10.97 

10.95 

10.93 

10.90 

42 

11.31 

11.28 

11.26 

11.24 

11.21 

11.19 

11.17 

43 

11.57 

11.55 

11.52 

11.50 

11.47 

11.45 

11.42 

44 

11.83 

11.81 

11.78 

11.76 

11.73 

11.71 

11.69 

45 

12.09 

12.07 

12.05 

12.02 

12.00 

11.97 

11.94 

46 

12.36 

12.33 

12.31 

12.28 

12.26 

12.23 

12.21 

47 

12.62 

12.60 

12.57 

12.54 

12.52 

12.49 

12.47 

48 

12.88 

12.86 

12.83 

12.81 

12.78 

12.75 

12.73 

49 

13.15 

13.12 

13.09 

13.07 

13.04 

13.01 

12.99 

50 

13.41 

13.39 

13.36 

13.33 

13.30 

13.27 

13.25 

51 

13.68 

13.65 

13.62 

13.59 

13.56 

13.53 

13.51 

52 

13.94 

13.91 

13.88 

13.85 

13.82 

13.79 

13.77 

53 

14.20 

14.17 

14.14 

14.11 

14.08 

14.06 

14.02 

54 

14.47 

14.44 

14.41 

14.38 

14.35 

14.32 

14.29 

55 

14.73 

14.70 

14.67 

14.64 

14.61 

14.58 

14.55 

56 

14.99 

14.96 

14.93 

14.90 

14.87 

14.84 

14.81 

57 

15.26 

15.23 

15.19 

15.16 

15.13 

15.10 

15.07 

58 

15.52 

15.49 

15.46 

15.42 

15.39 

15.36 

15.33 

59 

15.78 

15.75 

15.72 

15.69 

15.65 

15.62 

15.59 

60 

16.05 

16.01 

15.98 

15.95 

15.91 

15.88 

15.85 

61 

16.31 

16.28 

16.24 

16.21 

16.18 

16.14 

16.11 

62 

16.57 

16.54 

16.51 

16.47 

16.44 

16.40 

16.37 

63 

16.84 

16.80 

16.77 

16.73 

16.70 

16.66 

16.63 

64 

17.10 

17.07 

17.03 

17.00 

16.96 

16.92 

16.89 

65 

17.37 

17.33 

17.29 

17.26 

17.22 

17.19 

17.15 

66 

17.63 

17.59 

17.56 

17.52 

17.48 

17.45 

17.41 

67 

17.89 

17.86 

17.82 

17.78 

17.74 

17.71 

17.67 

68 

18.16 

18.12 

18.08 

18.04 

18.00 

17.97 

17.93 

69 

18.42 

18.38 

18.35 

18.31 

18.27 

18.23 

18.19 

70 

18.68 

18.65 

18.61 

18.57 

18.53 

18.49 

18.45 

71 

18.95 

18.91 

18.87 

18.83 

18.79 

18.75 

18.71 

72 

19.21 

19.17 

19.13 

19.09 

19.05 

19.01 

18.97 

73 

19.48 

19.44 

19.40 

19.35 

19.31 

19.27 

19.23 

74 

19.74 

19.70 

19.66 

19.62 

19.57 

19.53 

19.49 

75 

20.00 

19.96 

19.92 

19.88 

19.84 

19.80 

19.75 

76 

20.27 

20.22 

20.18 

20.14 

20.10 

20.06 

20.01 

77 

20.49 

20.45' 

20.40 

20.36 

20.32 

20.27 

78 

20.75 

20.71 

20.66 

20.62 

20.58 

20.54 

79 

20.97 

20.93 

20.88 

20.84 

20.80 

80 

IX. 

POUNDS  SOLIDS  PER  CUBIC  FOOT  IN  SUGAR  SOLUTIONS 

Calculated  for  Wiechmann,  Sugar  Analysis,  from  the 
following  data  taken  from  Everett:  Physical  Units  and 
Constants. 

1  cubic  centimeter  of  water  at  17.5°  C.  weighs  0.9987605 
gram. 

1  cubic  foot  =  283 16  cubic  centimeters. 

1  kilogram  =  2.2046212  Ibs. 

Hence  1  cubic  foot  of  water  at  17.5°  C.  weighs  62.3487  Ibs. 

FORMULAE. 


I.  62.3487  X Specific  Gravity  of  Sugar  solution. 

X  Degree  Brix 

Pounds  Solids  per  Cubic  Foot. 


TT    Result  obtained  by  I.  X Degree  Brix 
100 


276 


SUGAR  ANALYSIS 


IX. 


Degree 
Baume1. 

Degree 
Brix. 

Specific 
Gravity. 

Lbs.  solids 
in  1  cu.  ft. 

Degree 
Baum6. 

Degree 
Brix. 

Specific 
Gravity. 

Lbs.  solids 
in  1  cu.  ft. 

0.0 

0.0 

1  .  00000 

o.oou 

26.5 

47.7 

1.220lb 

36.289 

0.5 

0.9 

1.00349 

0.563 

27.0 

48.7 

1.22564 

37.215 

1.0 

1.8 

1.00701 

1.130 

27.5 

49.6 

1.23058 

38.056 

1.5 

2.6 

1.01015 

1.638 

28.0 

50.5 

1.23555 

38.903 

2.0 

3.5 

1.01371 

2.212 

28.5 

51.5 

1.24111 

39.852 

2.5 

4.4 

1.01730 

2.791 

29.0 

52.4 

1.24614 

40.712 

3.0 

5.3 

1.02091 

3.374 

29.5 

53.4 

1.25177 

41.677 

3.5 

6.2 

1.02454 

3.960 

30.0 

54.3 

1.25687 

42.552 

4.0 

7.0 

1.02779 

4.486 

30.5 

55.2 

1.26200 

43.434 

4.5 

7.9 

1.03146 

5.081 

31.0 

56.2 

1.26773 

44.421 

5.0 

8.8 

1.03517 

5.680 

31.5 

57.2 

1.27351 

45.418 

5.5 

9.7 

1.03889 

6.283 

32.0 

58.1 

1.27874 

46.322 

6.0 

10.6 

1.04264 

6.891 

32.5 

59.1 

1.28459 

47.335 

6.5 

11.5 

1.04641 

7.503 

33.0 

60.0 

1.28989 

48.254 

7.0 

12.4 

1.05021 

8.119 

33.5 

61.0 

1.29581 

49.283 

7.5 

13.2 

1.05361 

8.671 

34.0 

61.9 

1.30117 

50.217 

8.0 

14.1 

1.05746 

9.296 

34.5 

62.9 

1.30717 

51.264 

8.5 

15.0 

1.06133 

9.926 

35.0 

63.9 

1.31320 

52.319 

9.0 

15.9 

1.06522 

10.560 

35.5 

64.9 

1.31928 

53.384    • 

9.5 

16.8 

1.06914 

11.199 

36.0 

65.8 

1.32478 

54.350 

10.0 

17.7 

1.07309 

11.842 

36.5 

66.8 

1.33093 

55.432 

10.5 

18.6 

1.07706 

12.491 

37.0 

67.8 

1.33712 

56.523 

11.0 

19.5 

1.08106 

13.144 

37.5 

68.8 

1.34335 

57.624 

11.5 

20.4 

.08509 

13.801 

38.0 

69.8 

1.34962 

58.735 

12.0 

21.3 

.08914 

14.464 

38.5 

70.7 

1  .  35530 

59.742 

12.5 

22.2 

.09321 

15.132 

39.0 

71.7 

1.36164 

60.871 

13.0 

23.1 

.09732 

15.804 

39.5 

72.7 

1.36803 

62.009 

13.5 

24.0 

.  10145 

16.482 

40.0 

73.7 

1.37446 

63.158 

14.0 

24.9 

.  10560 

17.164 

40.5 

74.7 

1.38092 

64.316 

14.5 

25.8 

.  10979 

17.852 

41.0 

75.7 

1.38743 

65.484 

15.0 

26.7 

.11400 

18.545 

41.5 

76.7 

1.39397 

66.662 

15.5 

27.6 

.11824 

19.243 

42.0 

77.7 

1.40056 

67.850 

16.0 

28.5 

.  12250 

19.946 

42.5 

78.8 

1.40785 

69.169 

16.5 

29.4 

.  12679 

20.655 

43.0 

79.8 

1.41452 

70.378 

17.0 

30.3 

1.13111 

21.369 

43.5 

80.8 

1.42123 

71.598 

17.5 

31.2 

1.13545 

22.088 

44.0 

81.8 

1.42798 

72.829 

18.0 

32.1 

1.13983 

22.812 

44.5 

82.8 

1.43478 

74.070 

18.5 

33.0 

.  14423 

23.543 

45.0 

83.9 

1.44229 

75.447 

19.0 

33.9 

.  14866 

24.278 

45.5 

84.9 

1.44917 

76.710 

19.5 

34.8 

.  15312 

25.020 

46.0 

85.9 

1.45609 

77.985 

20.0 

35.7 

.15760 

25.766 

46.5 

87.0 

1.46374 

79.398 

20.5 

36.6 

.  16212 

26.519 

47.0 

88.0 

1.47074 

80.695 

21.0 

37.6 

.16717 

27.362 

47.5 

89.1 

1.47849 

82.134 

21.5 

38.5 

.17174 

28.127 

48.0 

90.1 

1  .  48558 

83.454 

22.0 

39.4 

1.17635 

28.897 

48.5 

91.2 

1.49342 

84.919 

22.5 

40.3 

1  .  18098 

29.674 

49.0 

92.3 

1  .  50130 

86.397 

23.0 

41.2 

1  .  18564 

30.456 

49.5 

93.3 

1.50852 

87.753 

23.5 

42.2 

1  .  19086 

31.333 

50.0 

94.4 

1.51649 

89.256 

24.0 

43.1 

1  .  19558 

32.128 

50.5 

95.5 

1.52449 

90.773 

24.5 

44.0 

1.20033 

32.929 

51.0 

96.6 

1.53254 

92.303 

25.0 

44.9 

1.20512 

33.737 

51.5 

97.7 

1.54068 

93.850 

25.5 

45.9 

1.21046 

34.641 

52.0 

98.8 

1.54890 

95.413 

26.0 

46.8 

1.21531 

35.462 

52.5 

99.9 

1.55711 

96.987 

X. 


FACTORS  FOR  THE  CALCULATION  OF  CLERGET 
INVERSIONS. 

Calculated   for   Wiechmann,   Sugar   Analysis,    by    the 
formula: 

100 


Factor  = 


142.66  ~ 


278 


SUGAR  ANALYSIS 


X. 


Temperature. 

Factor. 

Temperature. 

Factor. 

10° 

0.7257 

21° 

0.7567 

11 

0.7291 

22 

0.7595 

12 

0.7317 

23 

0.7624 

13 

0.7344 

24 

0.7653 

14 

0.7371 

25 

0.7683 

15 

0.7397 

26 

0.7712 

16 

0.7426 

27 

0.7742 

17 

0.7454 

28 

0.7772 

18 

0.7482 

29 

0.7802 

19 

0.7510 

30 

0.7833 

20 

0.7538 

XI. 

DETERMINATION  OF  TOTAL  SUGAR. 
German  Government:  Law  of  July  9,  1887. 


280 


SUGAR  ANALYSIS 


XI. 


Mgr. 

Sucrose. 

Mgr. 
Copper. 

Mgr. 

Sucrose. 

Mgr. 
Copper. 

Mgr. 
Sucrose. 

Mgr. 
Copper. 

Mgr. 

Sucrose. 

Mgr. 
Copper. 

40 

79.0 

73 

145.2 

106 

208.6 

139 

269.1 

41 

81.0 

74 

147.1 

107 

210.5 

140 

270.9 

42 

83.0 

75 

149.1 

108 

212.3 

141 

272.7 

43 

85.2 

76 

151.0 

109 

214.2 

142 

274.5 

44 

87.2 

77 

153.0 

110 

216.1 

143 

276.3 

45 

89.2 

78 

155.0 

111 

217.9 

144 

278.1 

46 

91.2 

79 

156.9 

112 

219.8 

145 

279.9 

47 

93.3 

80 

158.9 

113 

221.6 

146 

281.6 

48 

95.3 

81 

160.8 

114 

223.5 

147 

283.4 

49 

97.3 

82 

162.8 

115 

225.3 

148 

285.2 

50 

99.3 

83 

164.7 

116 

227.2 

149 

286.9 

51 

101.3 

84 

166.6 

117 

229.0 

150 

288.8 

52 

103.3 

85 

168.6 

118 

230.9 

151 

290.5 

53 

105.3 

86 

170.5 

119 

232.8 

152 

292.3 

54 

107.3 

87 

172.4 

120 

234.6 

153 

294.0 

55 

109.4 

88 

174.3 

121 

236.4 

154 

295.7 

56 

111.4 

89 

176.3 

122 

238.3 

155 

297.5 

57 

113.4 

90 

178.2 

123 

240.2 

156 

299.2 

58 

115.4 

91 

180.1 

124 

242.0 

157 

300.9 

59 

117.4 

92 

182.0 

125 

243.9 

158 

302.6 

60 

119.5 

93 

183.9 

126 

245.7 

159 

304.4 

61 

121.5 

94 

185.8 

127 

247.5 

160 

306.1 

62 

123.5 

95 

187.8 

128 

249.3 

161 

307.8 

63 

125.4 

96 

189.7 

129 

251.2 

162 

309.5 

64 

127.4 

97 

191.6 

130 

252.9 

163 

311.3 

65 

129.4 

98 

193.5 

131 

254.7 

164 

313.0 

66 

131.4 

99 

195.4 

132 

256.5 

165 

314.7 

67 

133.4 

100 

197.3 

133 

258.3 

166 

316.4 

68 

135.3 

101 

199.2 

134 

260.1 

167 

318.1 

69 

137.3 

102 

201.1 

135 

261.9 

168 

319.9 

70 

139.3 

103 

202.9 

136 

263.7 

169 

321.6 

71 

141.3 

104 

204.8 

137 

265.5 

170 

323.3 

72 

143.2 

105 

206.7 

138 

267.3 

XII. 

DETERMINATION  OF  INVERT  SUGAR 
VOLUMETRIC  METHOD. 

(Using  Fehling's  Solution.) 
5  grams  to  100  cubic  centimeters. 

Divide  1.00  by  the  number  of  cubic  centimeters  used 
of  above  solution  and  multiply  result  by  100. 


282 


SUGAR  ANALYSIS 


XII. 


Number 
of  c.c. 
used. 

Per  Cent 
of  Invert 
Sugar. 

Number 
of  c.c. 
used. 

Per  Cent 
of  Invert 
Sugar. 

Number 
of  c.c. 
used. 

Per  Cent 
of  Invert 
Sugar. 

Number 
of  c.c. 
used. 

Per  Cent 
of  Invert 

Sugar. 

1 

100.00 

26 

3.85 

51 

1.96 

76 

1.32 

2 

50.00 

27 

3.70 

52 

1.92 

77 

1.30 

3 

33.33 

28 

3.57 

53 

1.89 

78 

1.28 

4 

25.00 

29 

3.45 

54 

1.85 

79 

1.27 

5 

20.00 

30 

3.33 

55 

1.82 

80 

.25 

6 

16.67 

31 

3.23 

56 

1.79 

81 

.23 

7 

14.29 

32 

3.13 

57 

1.75 

82 

.22 

8 

12.50 

33 

3.03 

58 

1.72 

83 

.20 

9 

11.11 

34 

2.94 

59 

1.69 

84 

.19 

10 

10.00 

35 

2.86 

60 

1.67 

85 

.18 

11 

9.09 

36 

2.78 

61 

1.64 

86 

1.16 

12 

8.33 

37 

2.70 

62 

1.61 

87 

1.15 

13 

7.69 

38 

2.63 

63 

1.59 

88 

1.14 

14 

7.14 

39 

2.56 

64 

1.56 

89 

1.12 

15 

6.67 

40 

2.50 

65 

1.54 

90 

1.11 

16 

6.25 

41 

2.44 

66 

1.52 

91 

1.10 

17 

5.88 

42 

2.38 

67 

1.49 

92 

1.09 

18 

5.55 

43 

2.33 

68 

1.47 

93 

1.08 

19 

5.26 

44 

2.27 

69 

1.45 

94 

1.06 

20 

5.00 

45 

2.22 

70 

1.43 

95 

1.05 

21 

4.76 

46 

2.17 

71 

1.41 

96 

1.04 

22 

4.55 

47 

2.13 

72 

1.39 

97 

1.03 

23 

4.35 

48 

2.08 

73 

1.37 

98 

1.02 

24 

4.17 

49 

2.04 

74 

1.35 

99 

1.01 

25 

4.00 

50 

2.00 

75 

1.33 

100 

1.00 

XIII. 

DETERMINATION  OF  INVERT-SUGAR. 
GRAVIMETRIC  METHOD. 

(Using  Fehling's  Solution.) 
HERZFELD,   HILLER.   MEISSL. 


284 


SUGAR  ANALYSIS 


XIII. 


S    I. 

Z=200 
mgr. 

175  mgr. 

150  mgr. 

125  mgr. 

100  mgr. 

75  mgr. 

50  mgr. 

0     100 

56.4 

55.4 

54.5 

53.8 

53.2 

53.0 

53.0 

10     90 

56.3 

55.3 

54.4 

53.8 

53.2 

52.9 

52.9 

20     80 

56.2 

55.2 

54.3 

53.7 

53.2 

52  7 

52.7 

30     70 

56.1 

55.1 

54.2 

53.7 

53.2 

52.6 

52.6 

40     60 

55.9 

55.0 

54.1 

53.6 

53.1 

52.5 

52.4 

50     50 

55.7 

54.9 

54.0 

53.5 

53.1 

52.3 

52.2 

61     40 

55.6 

54.7 

53.8 

53.2 

52.8 

52.1 

51.9 

70     30 

55.5 

54.5 

53  5 

52.9 

52.5 

51.9 

51.6 

80     fO 

55.4 

54.3 

53.3 

52.7 

52.2 

51.7 

51.3 

90     10 

54.6 

53.6 

53.1 

52.6 

52.1 

51.6 

51.2 

91     9 

54.1 

53.6 

52.6 

52.1 

51.6 

51.2 

50.7 

92     8 

53.6 

53.1 

52.1 

51.6 

51.2 

50.7 

50.3 

93     7 

53.6 

53.1 

52.1 

51.2 

50.7 

50.3 

49.8 

94     6 

53.1 

52.6 

51.6 

50.7 

50.3 

49.8 

48.9 

95     5 

52.6 

52.1 

51.2 

50.3 

49.4 

48.9 

48.5 

96    4 

52.1 

51.2 

50.7 

49.8 

48.9 

47.7 

46.9 

97     3 

50.7 

50.3 

49.8 

48.9 

47.7 

46.2 

45.1 

98    2 

49.9 

48.9 

48.5 

47.3 

45.8 

43.3 

40.0 

99     1 

47.7 

47.3 

46.5 

45.1 

43.3 

41.2 

38.1 

XIV. 

SOLUBILITY  OF  SUCROSE  IN   WATER. 

(From  0°  to  100°  C.) 

HERZFELD. 


286 


SUGAR  ANALYSIS 


XIV. 


Temp.  °  C. 

Percentage 
Sucrose. 

Temp.  °  C. 

Percentage 
Sucrose. 

Temp.  °  C. 

Percentage 
Sucrose. 

0 

64.18 

34 

69.38 

68 

75.80 

1 

64.31 

35 

69.55 

69 

76.01 

2 

64.45 

36 

69.72 

70 

76.22 

3 

64.59 

37 

69.89 

71 

76.43 

4 

64.73 

38 

70.06 

72 

76.64 

5 

64.87 

39 

70.24 

73 

76.85 

6 

65.01 

40 

70.42 

74 

77.06 

7 

65.15 

41 

70.60 

75 

77.27 

8 

65.29 

42 

70.78 

76 

77.48 

9 

65.43 

43 

70.96 

77 

77.70 

10 

65-58 

44 

71.14 

78 

77.92 

11 

65.73 

45 

71.32 

79 

78.14 

12 

65.88 

46 

71.50 

80 

78.36 

13 

66.03 

47 

71.68 

81 

78.58 

14 

66.18 

48 

71.87 

82 

78.80 

15 

66.33 

49 

72.06 

83 

79.02 

16 

66.48 

50 

72.25 

84 

79.24 

17 

66.63 

51 

72.44 

85 

79.46 

18 

66.78 

52 

72.63 

86 

79.69 

19 

66.93 

53 

72.82 

87 

79.92 

20 

67.09 

54 

73.01 

88 

80.15 

21 

67.25 

55 

73.20 

89 

80.38 

22 

67.41 

56 

73.39 

90 

80.61 

23 

67.57 

57 

73.58 

91 

80.84 

24 

67.73 

58 

73.78 

92 

81.07 

25 

67.89 

59 

73.98 

9} 

81.30 

26 

68.05 

60 

74.18 

94 

81.53 

27 

68.21 

61 

74.38 

95 

81.77 

28 

68.37 

62 

74.58 

96 

82.01 

29 

68.53 

63 

74.78 

97 

82.25 

30 

68.70 

64 

74.98 

98 

82.49 

31 

68.87 

65 

75.18 

99 

82.73 

32 

69.04 

66 

75.38 

100 

82.79 

33 

69.21 

67 

75.59 

XV. 

DETERMINATION  OF  DEXTROSE. 

From  E.  Wein,  Tabellen  zur  Quantitativen  Bestimmung 
der  Zuckerarten. 

F.  ALLIHN. 


288 


SUGAR  ANALYSIS 


XV. 


Mgr. 
Copper. 

Mgr. 
Dextrose. 

Mgr. 
Copper. 

Mgr. 

Dextrose. 

Mgr. 
Copper. 

Mgr. 

Dextrose. 

1 

!  Mgr. 
|  Copper. 

Mgr. 
Dextrose. 

10 

6.1 

58 

29.8 

106 

54.0 

154 

78.6 

11 

6.6 

59 

30.3 

107 

54.5 

155 

79.1 

12 

7.1 

60 

30.8 

108 

55.0 

156 

79.6 

13 

7.6 

61 

31.3 

109 

55.5 

157 

80.1 

14 

8.1 

62 

31.8 

110 

56.0 

158 

80.7 

15 

8.6 

63 

32.3 

111 

56.5 

159 

81.2 

16 

9.0 

64 

32.8 

112 

57.0 

160 

81.7 

17 

9.5 

65 

33.3 

113 

57.5 

161 

82.2 

18 

10.0 

66 

33.8 

114 

58.0 

162 

82.7 

19 

10.5 

67 

34.3 

115 

58.6 

163 

83.3 

20 

11.0 

68 

34.8 

116 

59.1 

164 

83.8 

21 

11.5 

69 

35.3 

117 

59.6 

165 

84.3 

22 

12.0 

70 

35.8 

118 

60.1 

166 

84.8 

23 

12.5 

71 

36.3 

119 

60.6 

167 

85.3 

24 

13.0 

72 

36.8 

120 

61.1 

168 

85.9 

25 

13.5 

73 

37.3 

121 

61.6 

169 

86.4 

26 

14.0 

74 

37.8 

122 

62.1 

170 

86.9 

27 

14.5 

75 

38.3 

123 

62.6 

171 

87.4 

28 

15.0 

76 

38.8 

124 

63.1 

.  172 

87.9 

29 

15.5 

77 

39.3 

125 

63.7 

1  173 

88.5 

30 

16.0 

78 

39.8 

126 

64.2 

1  174 

89.0 

31 

16.5 

79 

40.3 

127 

64.7 

175 

89.5 

32 

17.0 

80 

40.8 

128 

65.2 

176 

90.0 

33 

17.5 

81 

41.3 

129 

65.7 

177 

90.5 

34 

18.0  . 

82 

41.8 

130 

66.2 

178 

91.1 

35 

18.5 

83 

42.3 

131 

66.7 

179 

91.6 

36 

18.9 

84 

42.8 

132 

67.2 

180 

92.1 

37 

19.4 

85 

43.4 

133 

67.7 

181 

92.6 

38 

19.9 

86 

43.9 

134 

68.2 

182 

93.1 

39 

20.4 

87 

44.4 

135 

68.8 

183 

93.7 

40 

20.9 

88 

44.9 

136 

69.3 

184 

94.2 

41 

21.4 

89 

45.4 

137 

69.8 

185 

94.7 

42 

21.9 

90 

45.9 

138 

70.3 

186 

95.2 

43 

22.4 

91 

46.4 

139 

70.8 

187 

95.7 

44 

22.9 

92 

46.9 

140 

71.3 

188 

96.3 

45 

23.4 

93 

47.4 

141 

71.8 

189 

96.8 

46 

23.9 

94 

47.9 

142 

72.3 

190 

97.3 

47 

24.4 

95 

48.4 

143 

72.9 

191 

97.8 

48 

24.9 

96 

48.9 

144 

73.4 

192 

98.4 

49 

25.4 

97 

49.4 

145 

73.9 

193 

98.9 

50 

25.9 

98 

49.9 

146 

74.4 

194 

99.4 

51 

26.4 

99 

50.4 

147 

74.9 

195 

100.0 

52 

26.9 

100 

50.9 

148 

75.5 

196 

100.5 

53 

27.4 

101 

51.4 

149 

76.0 

197 

101.0 

54 

27.9 

102 

51.9 

150 

76.5 

198 

101.5 

55 

28.4 

103 

52.4 

151 

77.0 

199 

102.0 

56 

28.8 

104 

52.9 

152 

77.5 

200 

102.6 

57 

29.3 

105 

53.5 

153 

78.1 

201 

103.2 

TABLES 


289 


XV. 


Mgr. 
Copper. 

Mgr. 
Dextrose. 

Mgr. 
Copper. 

Mgr. 
Dextrose. 

Mgr. 
Copper. 

Mgr. 
Dextrose. 

Mgr. 
Copper. 

Mgr. 
Dextrose. 

202 

103.7 

250 

129.2 

298 

155.4 

346 

182.1 

203 

104.2 

251 

129.7 

299 

156.0 

347 

182.6 

204 

104.7 

252 

130.3 

300 

156.5 

348 

183.2 

205 

105.3 

253 

130.8 

301 

157.1 

349 

183.7 

206 

105.8 

254 

131.4 

302 

157.6 

350 

184.3 

207 

106.3 

255 

131.9 

303 

158.2 

351 

184.9 

208 

106.8 

256 

132.4 

304 

158.7 

352 

185.4 

209 

107.4 

257 

133.0 

305 

159.3 

353 

186.0 

210 

107.9 

258 

133.5 

306 

159.8 

354 

186.6 

211 

108.4 

259 

134.1 

307 

160.4 

355 

187.2 

212 

109.0 

260 

134.6 

308 

160.9 

356 

187.7 

213 

109.5 

261 

135.1 

309 

161.5 

357 

188.3 

214 

110.0 

262 

135.7 

310 

162.0 

358 

188.9 

215 

110.6 

263 

136.2 

311 

162.6 

359 

189.4 

216 

111.1 

264 

136.8 

312 

163.1 

360 

190.0 

217 

111.6 

265 

137.3 

313 

163.7 

361 

190.6 

218 

112.1 

266 

137.8 

314 

164.2 

362 

191.1 

219 

112.7 

267 

138.4 

315 

164.8 

363 

191.7 

220 

113.2 

268 

138.9 

316 

165.3 

364 

192.3 

221 

113.7 

269 

139.5 

317 

165.9 

365 

192.9 

222 

114.3 

270 

140.0 

318 

166.4 

366 

193.4 

223 

114.8 

271 

140.6 

319 

167.0 

367 

194.0 

224 

115.3 

272 

141.1 

320 

167.5 

368 

194.6 

225 

115.9 

273 

141.7 

321 

168.1 

369 

195.1 

226 

116.4 

274 

142.2 

322 

168.6 

370 

195.7 

227 

116.9 

275 

142.8 

323 

169.2 

371 

196.3 

228 

117.4 

276 

143.3 

324 

169.7 

372 

196.8 

229 

118.0 

277 

143.9 

325 

170.3 

373 

197.4 

230 

118.5 

278 

144.4 

326 

170.9 

374 

198.0 

231 

119.0 

279 

145.0 

327 

171.4 

375 

198.6 

232 

119.6 

280 

145.5 

328 

172.0 

376 

199.1 

233 

120.1 

281 

146.1 

329 

172.5 

377 

199.7 

234 

120.7 

282 

146.6 

330 

173.1 

378 

200.3 

235 

121.2 

283 

147.2 

331 

173.7 

379 

200.8 

236 

121.7 

284 

147.7 

332 

174.2 

380 

201.4 

237 

122.3 

285 

148.3 

333 

174.8 

381 

202.0 

238 

122.8 

286 

148.8 

334 

175.3 

382 

202.5 

239 

123.4 

287 

149.4 

335 

175.9 

383 

203.1 

240 

123.9 

288 

149.9 

336 

176.5 

384 

203.7 

241 

124  .4 

289 

150.5 

337 

177.0 

385 

204.3 

242 

125.0 

290 

151.0 

338 

177.6 

386 

204.8 

243 

125.5 

291 

151.6 

339 

178.1 

387 

205.4 

244 

126.0 

292 

152.1 

340 

178.7 

388 

206.0 

245 

126.6 

293 

152.7 

341 

179.3 

389 

206.5 

246 

127.1 

294 

153.2 

342 

179.8 

390 

207.1 

247 

127.6 

295 

'153.8 

343 

180.4 

391 

207.7 

248 

128.1 

296 

154.3 

344 

180.9 

392 

208.3 

249 

128.7 

297 

154.9 

345 

181.5 

393 

208.8 

290 


SUGAR  ANALYSIS 


XV. 


Mgr. 
Copper. 

Mgr. 
Dextrose. 

Mgr. 
Copper. 

Mgr. 
Dextrose. 

Mgr. 
Copper. 

Mgr. 
Dextrose. 

Mgr. 
Copper. 

Mgr. 
Dextrose. 

394 

209.4 

412 

219.9 

430 

230.4 

447 

240.4 

395 

210.0 

413 

220.4 

431 

231.0 

448 

241.0 

396 

210.6 

414 

221.0 

432 

231.6 

449 

241.6 

397 

211.2 

415 

221.6 

433 

232.2 

450 

242.2 

398 

211.7 

416 

222.2 

434 

232.8 

451 

242.8 

399 

212.3 

417 

222.8 

435 

233.4 

452 

243.4 

400 

212.9 

418 

223.3 

436 

233.9 

453 

244.0 

401 

213.5 

419 

223.9 

437 

234.5 

454 

244.6 

402 

214.1 

420 

224.5 

438 

235.1 

455 

245.2 

403 

214.6 

421 

225.1 

439 

235.7 

456 

245.7 

404 

215.2 

422 

225.7 

440 

236.3 

457 

246.3 

405 

215.8 

423 

226.3 

441 

236.9 

458 

246.9 

406 

216.4 

424 

226.9 

442 

237.5 

459 

247.5 

407 

217.0 

425 

227.5 

443 

238.1 

460 

248.1 

408 

217.5 

426 

228.0 

444 

238.7 

461 

248.7 

409 

218.1 

427 

228.6 

445 

239.3 

462 

249.3 

410 

218.7 

428 

229.2 

446 

239.8 

463 

249.9 

411 

219.3 

429 

229.8 

XVI 

DETERMINATION  OF  LEVULOSE. 
HONIG  AND  JESSER. 


292 


SUGAR  ANALYSIS 


XVI. 


Mgr. 
Levulose. 

Mgr. 
Copper. 

Mgr. 
Levulose. 

Mgr. 
Copper. 

Mgr. 
Levulose. 

Mgr. 
Copper. 

10 

13.73 

95 

170.03 

180 

315.33 

15 

23.23 

100 

178.88 

185 

323.53 

20 

32.69 

105 

187.69 

190 

331.67 

25 

42.12 

110 

196.47 

195 

339.81 

30 

51.50 

115 

205.25 

200 

347.91 

35 

60.85 

120 

213.90 

205 

355.97 

40 

70.15 

125 

222.56 

210 

363.99 

45 

79.42 

130 

231  .  19 

215 

371.98 

50 

88.65 

135 

239.77 

220 

379.92 

55 

97.85 

140 

248.32 

225 

387.83 

60 

107.10 

145 

256.84 

230 

395.70 

65 

116.12 

150 

265.32 

235 

403.53 

70 

125.20 

155 

273.76 

240 

411.32 

75 

134.24 

160 

282.16 

245 

419.03 

80 

143.24 

165 

290.48 

250 

426.73 

85 

152.22 

170 

298.85 

90 

161.14 

175 

307.09 

XVII. 

DENSITY  OF  WATER  AT  THE  TEMPERATURES  FROM  0° 
TO  50°  CENTIGRADE,  RELATIVE  TO  ITS  DENSITY  AT 
4°  CENTIGRADE. 

ROSETTI. 

Based  on  results  obtained  by  Kopp,  Despretz,  Hagen, 
Matthiessen,  Ilosetti. 


294 


SUGAR  ANALYSIS 


XVII. 


Temperature: 
Degrees  Centi- 
grade. 

Density  of  Water 
relative  to  its 
Density  at  4°  C. 

Temperature: 
Degrees  Centi- 
grade. 

Density  of  Water 
relative  to  its 
Density  at  4°  C. 

0° 

0.99987 

25° 

0.99712 

1 

0.99993 

26 

0.99687 

2 

0.99997 

27 

0.99660 

3 

0.99999 

28 

0.99633 

4 

1.00000 

29 

0.99605 

5 

0.99999 

30 

0.99577 

6 

0.99997 

31 

0.99547 

7 

0.99993 

32 

0.99517 

8 

0.99989 

33 

0.99485 

9 

0.99982 

34 

0.99452 

10 

0.99975 

35 

0.99418 

11 

0.99966 

36 

0.99383 

12 

0.99955 

37 

0.99347 

13 

0.99943 

38 

0.99310 

14 

0.99930 

39 

0.99273 

15 

0.99916 

40 

0.99235 

16 

0.99900 

41 

0.99197 

17 

0.99884 

42 

0.99158 

18 

0.99865 

43 

0.99118 

19 

0.99846 

44 

0.99078 

20 

0.99826 

45 

0.99037 

21 

0.99805 

46    • 

0.98996 

22 

0.99783 

47 

0.98954 

23 

0.99760 

48 

0.98910 

24 

0.99737 

49 

0.98865 

50 

0.98819 

XVIII. 

TABLE  OF  FACTORS. 
MORSE. 


296 


SUGAR  ANALYSIS 
XVIII. 


Purity  of 
'  Molasses. 

Polarization  of  Sugar. 

100 

99.5 

99.0 

98.5 

93.0 

14.30 

15.40 

16.40 

17.60 

92.8 

13.90 

14.95 

15.90 

17.00 

92.6 

13.50 

14.50 

15.40 

16.45 

92.4 

13.15 

14.10 

14.95 

15.95 

92.2 

12.80 

13.70 

14.50 

15.45 

92.0 

12.50 

13.35 

14.10 

15.00 

91.8 

12.20 

13.00 

13.70 

14.55 

91.6 

11.90 

12.65 

13.35 

14.15 

91.4 

11.65 

12.30 

13.05 

13.75 

91.2 

11.35 

12.05 

12.65 

13.40 

91.0 

11.10 

11.75 

12.35 

13.05 

90.8 

10.85 

11.50 

12.05 

12.70 

90.6 

10.65 

11.25 

11.75 

12.40 

90.4 

10.40 

11.00 

11.50 

12.10 

90.2 

10.20 

10.70 

11.25 

11.80 

90.0 

10.00 

10.55 

11.00 

11.55 

89.8 

9.80 

10.30 

10.75 

11.25 

89.6 

9.60 

10.10 

10.55 

11.00 

89.4 

9.45 

10.00 

10.30 

10.80 

89.2 

9.25 

9.90 

10.10 

10.55 

89.0 

9.10 

9.70 

9.90 

10.35 

88.8 

8.95 

9.50 

9.70 

10.15 

88.6 

8.75 

9.35 

9.55 

9.95 

88.4 

8.60 

9.15 

9.35 

9.75 

88.2 

8.45 

9.00 

9.20 

9.55 

88.0 

8.35 

8.85 

9.00 

9.35 

87.8 

8.20 

8.70 

8.85 

9.20 

87.6 

8.05 

8.55 

8.70 

9.05 

87.4 

7.95 

8.40 

8.55 

8.85 

87.2 

7.80 

8.25 

8.40 

8.70 

87.0 

7.70 

8.15 

8.25 

8.55 

86.8 

7.60 

8.00 

8.15 

8.40 

86.6 

7.45 

7.85 

8.00 

8.30 

86.4 

7.35 

7.75 

7.90 

8.15 

86.2 

7.25 

7.65 

7.75 

8.00 

86.0 

7.15 

7.50 

7.65 

7.90 

85.8 

7.05 

7.40 

7.50 

7.80 

85.6 

6.95 

7.30 

7.40 

7.65 

85.4 

6.85 

7.20 

7.30 

7.55 

85.2 

6.75 

7.10 

7.20 

7.45 

85.0 

6.65 

7.00 

7.05 

7.32 

XIX. 

COMPARISON  OF  THERMOMETRIC  SCALES. 


=R+32. 


C  =  |(F-32)=|R. 
R-f(F-32)-|c. 


298 


SUGAR  ANALYSIS 


XIX. 

CENTIGRADE,  FAHRENHEIT,   REAUMUR. 


Centi- 
grade. 

Fahren- 
heit. 

Reaumur. 

Centi- 
grade. 

Fahren- 
heit. 

Reaumur. 

Centi- 
grade. 

Fahren- 
heit. 

Reaumur. 

o 

o 

o 

o 

o 

o 

o 

0 

o 

100 

212 

80 

53 

127.4 

42.4 

6 

42.8 

4.8 

99 

210.2 

79.2 

52 

125.6 

41.6 

5 

41 

4 

98 

208.4 

78.4 

51 

123.8 

40.8 

4 

39.2 

3.2 

97 

206.6 

77.6 

50 

122 

40 

3 

37.4 

2.4 

96 

204.8 

76.8 

49 

120.2 

39.2 

2 

35.6 

1.6 

95 

203 

76 

48 

118.4 

38.4 

1 

33.8 

0.8 

94 

201.2 

75.2 

47 

116.6 

37.6 

0 

32 

0 

93 

199.4 

74.4 

46 

114.8 

36.8 

-  1 

30.2 

-  0.8 

92 

197.6 

73.6 

45 

113 

36 

-  2 

28.4 

-  1.6 

91 

195.8 

72.8 

44 

111.2 

35.2 

-  3 

26.6 

-  2.4 

90 

194 

72 

43 

109.4 

34.4 

-  4 

24.8 

-  3.2 

89 

192.2 

71.2 

42 

107.6 

33.6 

-  5 

23 

-  4 

88 

190.4 

70.4 

41 

105.8 

32.8 

-  6 

21.2 

-  4.8 

87 

188.6 

69.6 

40 

104 

32 

-  7 

19.4 

-  5.6 

86 

186.8 

68.8 

39 

102.2 

31.2 

-  8 

17.6 

-  6.4 

85 

185 

68 

38 

100.4 

30.4 

-  9 

15.8 

-  7.2 

84 

183.2 

67.2 

37 

98.6 

29.6 

-10 

14 

0 

o 

83 

181.4 

66.4 

36 

96.8 

28.8 

-11 

12.2 

-  8.8 

82 

179.6 

65.6 

35 

95 

28 

-12 

10.4 

-  9.6 

81 

177.8 

64.8 

34 

93.2 

27.2 

-13 

8.6 

-10.4 

80 

176 

64 

33 

91.4 

26.4 

-14 

6.8 

-11.2 

79 

174.2 

63.2 

32 

89.6 

25.6 

-15 

5 

-12 

78 

172.4 

62.4 

31 

87.8 

24.8 

-16 

3.2 

-12.8 

77 

170.6 

61.6 

30 

86 

24 

-17 

1.4 

-13.6 

76 

168.8 

60.8 

29 

84.2 

23.2 

-18 

0.4 

-14.4 

75 

167 

60 

28 

82.4 

22.4 

-19 

-  2.2 

-15.2 

74 

165.2 

59.2 

27 

80.6 

21.6 

-20 

-  4 

-16 

73 

163.4 

58.4 

26 

78.8 

20.8 

-21 

-  5.8 

-16.8 

72 

161.6 

57.6 

25 

77 

20 

—22 

-  7.6 

-17.6 

71 

159.8 

56.8 

24 

75.2 

19.2 

-23 

-  9.4 

-18.4 

70 

158 

56 

23 

73.4 

18.4 

-24 

-11.2 

-19.2 

69 

156.2 

55.2 

22 

71.6 

17.6 

-25 

-13 

-20 

68 

154.4 

54.4 

21 

69.8 

16.8 

-26 

-14.8 

-20.8 

67 

152.6 

53.6 

20 

68 

16 

-27 

-16.6 

-21.6 

66 

150.8 

52.8 

19 

66.2 

15.2 

-28 

-18.4 

-22.4 

65 

149 

52 

18 

64.4 

14.4 

-29 

-20.2 

-23.2 

64 

147.2 

51.2 

17 

62.6 

13.6 

-30 

-22 

-24 

63 

145.4 

50.4 

16 

60.8 

12.8 

-31 

-23.8 

-24.8 

62 

143.6 

49.6 

15 

59 

12 

-32 

-25.6 

-25.6 

61 

141.8 

48.8 

14 

57.2 

11.2 

-33 

-27.4 

-26.4 

60 

140 

48 

13 

55.4 

10.4 

-34 

-29.2 

-27.2 

59 

138.2 

47.2 

12 

53.6 

9.6 

-35 

-31 

-28 

58 

136.4 

46.4 

11 

51.8 

8.8 

-36 

-32.8 

-28.8 

57 

134.6 

45.6 

10 

50 

8 

-37 

-34.6 

-29.6 

56 

132.8 

44.8 

9 

48.2 

7.2 

-38 

-36.4 

-30.4 

55 

131 

44 

8 

46.4 

6.4 

-39 

-38.2 

-31.2 

54 

129.2 

43.2 

7 

44.6 

5.6 

-40 

-40 

-32 

TABLES 


299 


XIX. 

FAHRENHEIT,  CENTIGRADE,   REAUMUR. 


Fah- 
ren- 
heit. 

Centi- 
grade. 

Reaumur. 

Fah- 
ren- 
heit. 

Centi- 
grade. 

R6aumur. 

Fah- 
ren- 
heit. 

Centi- 
grade. 

R6aumur. 

o 

o 

o 

o 

o 

0 

0 

o 

o 

212 

100 

80 

165 

73.89 

59.11 

118 

47.78 

38.22 

211 

99.44 

79.56 

164 

73.33 

58.67 

117 

47.22 

37.78 

210 

98.89 

79.11 

163 

72.78 

58.22 

116 

46.67 

37.33 

209 

98.33 

78.67 

162 

72.22 

57.78 

115 

46.11 

36.89 

208 

97.78 

78.22 

161 

71.67 

57.33 

114 

45.55 

36.44 

207 

97.22 

77.78 

160 

71.11 

56.89 

113 

45 

36 

206 

96.67 

77.33 

159 

70.55 

56.44 

112 

44.44 

35.56 

205 

96.11 

76.89 

158 

70 

56 

111 

43.89 

35.11 

204 

95.55 

76.44 

157 

69.44 

55.56 

110 

43.33 

34.67 

203 

95 

76 

156 

68.89 

55.11 

109 

42.78 

34.22 

202 

94.44 

75.56 

155 

68.33 

54.67 

108 

42.22 

33.78 

201 

93.89 

75.11 

154 

67.78 

54.22 

107 

41.67 

33.33 

200 

93.33 

74.67 

153 

67.22 

53.78 

106 

41.11 

32.89 

199 

92.78 

74.22 

152 

66.67 

53.33 

105 

40.55 

32.44 

198 

92.22 

73.78 

151 

66.11 

52.89 

104 

40 

32 

197 

91.67 

73.33 

150 

65.55 

52.44 

103 

39.44 

31.56 

196 

91.11 

72.89 

149 

65 

52 

102 

38.89 

31.11 

195 

90.55 

72.44 

148 

64.44 

51.56 

101 

38.33 

30.67 

1.94 

90 

72 

147 

63.89 

51.11 

100 

37.78 

30.22 

193 

89.44 

71.56 

146 

63.33 

50.67 

99 

37.22 

29.78 

192 

88.89 

71.11 

145 

62.78 

50.22 

98 

36.67 

29.33 

191 

88.33 

70.67 

144 

62.22 

49.78 

97 

36.11 

28.89 

190 

87.78 

70.22 

143 

61.67 

49.33 

96 

35.55 

28.44 

189 

87.22 

69.78 

142 

61.11 

48.89 

95 

35 

28 

188 

86.67 

69.33 

141 

60.55 

48.44 

94 

34.44 

27.56 

187 

86.11 

68.89 

140 

60 

48 

93 

33.89 

27.11 

186 

85.55 

68.44 

139 

59.44 

47.56 

92 

33.33 

26.67 

185 

85 

68 

138 

58.89 

47.11 

91 

32.78 

26.22 

184 

84.44 

67.56 

137 

58.33 

46.67 

90 

32.22 

25.78 

183 

83.89 

67.11 

136 

57.78 

46.22 

89 

31.67 

25.33 

182 

83.33 

66.67 

135 

57.22 

45.78 

88 

31.11 

24.89 

181 

82.78 

66.22 

134 

56.67 

45.33 

87 

30.55 

24.44 

180 

82.22 

65.78 

133 

56.11 

44.89 

86 

30 

24 

179 

81.67 

65.33 

132 

55.55 

44.44 

85 

29.44 

23.56 

178 

81.11 

64.89 

131 

55 

44 

84 

28.89 

23.11 

177 

80.55 

64.44 

130 

54.44 

43.56 

83 

28.33 

22.67 

176 

80 

64 

129 

53.89 

43.11 

82 

27.78 

22.22 

175 

79.44 

63.56 

128 

53.33 

42.67 

81 

27.22 

21.78 

174 

78.89 

63.11 

127 

52.78 

42.22 

80 

26.67 

21.33 

173 

78.33 

62.67 

126 

52.22 

41.78 

79 

26.11 

20.89 

172 

77.78 

62.22 

125 

51.67 

41.33 

78 

25.55 

20.44 

171 

77.22 

61.78 

124 

51.11 

40.89 

77 

25 

20 

170 

76.67 

61.33 

123 

50.55 

40.44 

76 

24.44 

19.56 

169 

76.11 

60.89 

122 

50 

40 

75 

23.89 

19.11 

168 

75.55 

60.44 

121 

49.44 

39.56 

74 

23.33 

18.67 

167 

75 

60 

120 

48.89 

39.11 

73 

22.78 

18.22 

166 

74.44 

59.56 

119 

48.33 

38.67 

72 

22.22 

17.78 

300 


SUGAR  ANALYSIS 


XIX. 


Fah- 
ren- 
heit. 

Centi- 
grade. 

Rfiaumur. 

Fah- 
ren- 
heit. 

Centi- 
grade. 

Reaumur. 

Fah- 
ren- 
heit. 

Centi- 
grade. 

Reaumur. 

o 

0 

o 

0 

o 

o 

0 

o 

O 

71 

21.67 

17.33 

33 

0.55 

0.44 

-  4 

-20 

-16 

70 

21.11 

16.89 

32 

0 

0 

-  5 

-20.55 

-16.44 

69 

20.55 

16.44 

31 

-  0.55 

-  0.44 

-  6 

-21.11 

-16.89 

68 

20 

16 

30 

-  1.11 

-  0.89 

-  7 

-21.67 

-17.33 

67 

19.44 

15.56 

29 

-  1.67 

-  1.33 

-  8 

-22.22 

-17.78 

66 

18.89 

15.11 

28 

—  2  22 

-  1.78 

-  9 

-22.78 

-18.22 

65 

18.33 

14.67 

27 

-  2.78 

-  2.22 

-10 

-23.33 

-18.67 

64 

17.78 

14.22 

26 

-  3.33 

-  2.67 

-11 

-23.89 

-19.11 

63 

17.22 

13.78 

25 

-  3.89 

-  3.11 

-12 

-24.44 

-19.56 

62 

16.67 

13.33 

24 

-  4.44 

-  3.56 

-13 

-25 

-20 

61 

16.11 

12.89 

23 

-  5 

-  4 

-14 

-25.55 

-20.44 

60 

15.55 

12.44 

22 

-5.55 

-  4.44 

-15 

-26.11 

-20.89 

59 

15 

12 

21 

-  6.11 

-  4.89 

-16 

-26.67 

-21.33 

58 

14.44 

11.56 

20 

-  6.67 

-  5.33 

-17 

-27.22 

-21.78 

57 

13.89 

11.11 

19 

-  7.22 

-  5.78 

-18 

-27.78 

-22.22 

56 

13.33 

10.67 

18 

-  7.78 

-  6.22 

-19 

-28.33 

-22.67 

55 

12.78 

10.22 

17 

-  8.33 

-  6.67 

-20 

-28.89 

-23.11 

54 

12.22 

9.78 

16 

-  8.89 

-  7.11 

-21 

-29.44 

-23.56 

53 

11.67 

9.33 

15 

-  9.44 

-  7.56 

-22 

-30 

-24 

52 

11.11 

8.89 

14 

-10 

-  8 

-23 

-30.55 

-24.44 

51 

10.55 

8.44 

13 

-10.55 

-  8.44 

-24 

-31.11 

-24.89 

50 

10 

8 

12 

-11.11 

-  8.89 

-25 

-31.67 

-25.33 

49 

9.44 

7.56 

11 

-11.67 

-  9.33 

-26 

-32.22 

-25.78 

48 

8.89 

7.11 

10 

-12.22 

-  9.78 

-27 

-32.78 

-26.22 

47 

8.33 

6.67 

9 

-12.78 

-10.22 

-28 

-33.33 

-26.67 

46 

7.78 

6.22 

8 

-13.33 

-10.67 

-29 

-33.89 

-27.11 

45 

7.22 

5.78 

7 

-13.89 

-11.11 

-30 

-34.44 

-27.56 

44 

6.67 

5.33 

6 

-14.44 

-11.56 

-31 

-35 

-28 

43 

6.11 

4.89 

5 

-15 

-12 

-32 

-35.55 

-28.44 

42 

5.55 

4.44 

4 

-15.55 

-12.44 

-33 

-36.11 

-28.89 

41 

5 

4 

3 

-16.11 

-12.89 

-34 

-36.67 

-29.33 

40 

4.44 

3.56 

2 

-16.67 

-13.33 

-35 

-37.22 

-29.78 

39 

3.89 

3.11 

1 

-17.22 

-13.78 

-36 

-37.78 

-30.22 

38 

3.33 

2.67 

0 

-17.78 

-14.22 

-37 

-38.33 

-30.67 

37 

2.78 

2.22 

-1 

-18.33 

-14.67 

-38 

-38.89 

-31.11 

36 

2.22 

1.78 

-2 

-18.89 

-15.11 

-39 

-39.44 

-31.56 

35 

1.67 

1.33 

-3 

-19.44 

-15.56 

-40 

-40 

-32 

34 

1.11 

0.89 

XX. 

TABLES    FOR    CONVERTING    CUSTOMARY    AND    METRIC 
WEIGHTS   AND   MEASURES. 

UNITED  STATES  COAST  AND  GEODETIC  SURVEY. 

OFFICE  OF  STANDARD  WEIGHTS  AND  MEASURES. 

T.  C.  MENDENHALL,  Superintendent. 

WASHINGTON,  D.  C.,  1890. 

\Authorized  Reprint.] 


302 


SUGAR  ANALYSIS 


XX. 

CUSTOMARY  TO  METRIC 


LINEAR. 

CAPACITY. 

5 

6 

I 

A 

B 

1 

1 

i 

•g 

£ 

a 

1|| 

o  2 

J 

22 

3 

o 

K 

M  . 

^Ig 

If 

3 
2 

3 
§ 

ll 

| 

1 

~a 

li 

1 

O 

q 

M 

1 

i 

s 

s 

<§ 

o 

1=   25.4000 

0.304801 

0.914402 

1.60935 

1=   3.70 

29.57 

0.94636 

3.78544 

2=   50.8001 

0.609601 

1.828 

S04 

3.21869 

2=   7.39 

59.15 

1.89272 

7.57088 

3=   76.2001 

0.914402 

2.743 

105 

4.82804 

3=11.09 

88.72 

2.83908 

11.35632 

4=101.6002 

1.219202 

3.657607 

6.43739 

4=14.79 

118.30 

3.78544 

15.14176 

5=127.0002 

1.524003 

4.572 

109 

8.04674 

5=18.48 

147.87 

4.73180 

18.92720 

6=152.4003 

1.828804 

5.486< 

111 

9.65608 

6  =  22.18 

177.44 

5.67816 

22.71264 

7=177.8003 

2.133604 

6.400813 

11.26543 

7=25.88 

207.02 

6.62452 

26.49808 

8  =  203.2004 

2.438405 

7.315 

>!.-> 

12.87478 

8=29.57 

236.59 

7.57088 

30.28352 

9  =  228.6004 

2.743205 

8.229616 

14.48412 

9  =  33.28 

266.16 

8.51724 

34.06896 

SQUARE. 

WEIGHT. 

sl 

><£ 

1 

j. 

1 

J| 

3 

If 

ll 
hi 

3 

0 

J. 

"03 

fi 

L 

Is 

S^ 

c  § 

"go 

IM 

o  | 

t 

03  o< 

P 

02 

1 

O 

£3 

IS 

Is 

1=   6.452 

9.290 

0.836 

0.4047 

1=   64.7989 

28.3495 

0.45359 

31.10348 

2=12.903 

18.581 

1.672 

0.8094 

2=129.5978 

56.6991 

0.90719 

62.20096 

3=19.355 

27.871 

2.508 

1.2141 

3=194.3968 

85.0486 

1.36078 

93.31044 

4  =  25.807 

37.161 

3.344 

1.6187 

4=259.1957 

113.3981 

1.81437 

124.41392 

5=32.258 

46.452 

4.181 

2.0234 

5  =  323.9946 

141.7476 

2.26796 

155.51740 

6=38.710 

55.742 

5.017 

2.4281 

6=388.7935 

170.0972 

2.72156 

186.62089 

7  =  45.161 

65.032 

5.853 

2.8328 

7  =  453.5924 

198.4467 

3.17515 

217.72437 

8  =  51.613 

74.323 

6.689 

3.2375 

8  =  518.3914 

226.7962 

3.62874 

248.82785 

9  =  58.065 

83.613 

7.525 

3.6422 

9  =  583.1903 

255.1457 

4.08233 

279.93133 

CUBIC. 

3     . 

B    ^ 

3 

|||| 

ill 

j 

f 

22*5 

ill 

1=   16.387 

0.02832 

0.765 

0. 

35242              1  chain 

=            20.1169       meters. 

2=   32.774 

0.05663 

1.529 

0 

70485              1  square  mil< 

;      =          259             hectares. 

3=   49.161 

0.08495 

2.294 

1. 

05727              1  fathom 

1.829         meters. 

4=   65.549 

0.11327 

3.058 

1. 

40969              1  nautical  mile  =        1853.27           meters. 

5  =   81.936 

0.14158 

3.823 

1. 

76211              1  foot  =0.304 

1801  meter,  9.4840158       log. 

6=   98.323 

0.16990 

4.587 

2. 

11454              1  avoir,  pour 

id   =         453.5924277  crams. 

7=114.710 
8=131.097 

0.19822 
0.22654 

5.352 
6.116 

2.46696       15432.35039'grains  =              1            kilogram. 
2.81938 

9=147.484 

0.25485 

6.881 

3. 

17181 

TABLES 

XX. 

METRIC   TO   CUSTOMARY 


303 


LINEAR. 

CAPACITY. 

t 

•a 

43 

2 

3 
g 

2 

| 

I 

I 

0 

4i 

S 

i 

3 
& 

3 

S 

£<n 

3 

3 

3 

«  • 

|SQ 

ii 

3 

!§ 

£ 

£ 

£ 

|1 

igs 

=  a 

£ 

11 

OOT 

• 

1 

S 

<u 

|o5 

8° 

S 

P 

^p; 

S 

S 

S 

M 

^ 

o 

5 

Q 

ffi 

1=   39.3700 

3.28083 

1.093611 

0.62137 

1  =  0.27 

0.338 

1.0567 

2.6417 

2.8375 

2=   78.7400 

6.56167 

2.187222 

1.24274 

2  =  0.54 

0.676 

2.1134 

5.2834 

5.6750 

3=118.1100 

9.84250 

3.280833 

1.86411 

3  =  0.81 

1.014 

3.1700 

7.9251 

8.5125 

4=157.4800 

13.12333 

4.374444 

2.48548 

4=1.08 

1.352 

4.2267 

10.5668 

11.3500 

5=196.8500 

16.40417 

5.468056 

3.10685 

5=1.35 

1.691 

5.2834 

13.2085 

14.1875 

6  =  236.2200 

19.68500 

6.561667 

3.72822 

6=1.62 

2.029 

6.3401 

15.8502 

17.0250 

7  =  275.5900 

22.96583 

7.655278 

4.34959 

7=1.89 

2.368 

7.3968 

18.4919 

19.8625 

8  =  314.9600 

26.24667 

8.748889 

4.97096 

8  =  2.16 

2.706 

8.4534 

21.1336 

22.7000 

9  =  354.3300 

29.52750 

9.842500 

5.59233 

9=2.43 

3.043 

9.5101 

23.7753 

25.5375 

SQUARE. 

WEIGHT. 

3  . 

TO  TO 

o 

o  . 

1 

Sri 

4 

Is 

11 

II 

S 

S 

S 

o 

P 

H 

B3  3 

nl 

ol 

£§ 

1 

l! 

l! 

P 

P 

|l 

P 

1 

50 

20 

ifw 

II 

02 

I 

w 

S 

M 

H 

M 

1  =  0.1550 

10.764 

1.196 

2.471 

1  =  0.01543 

15432.36 

3.5274 

2  20462 

2  =  0.3100 

21.528 

2.392 

4.942 

2  =  0.03 

)86 

30864.71 

7.0548 

4.40924 

3  =  0.4050 

32.292 

3.588 

7.413 

3  =  0.04 

330 

4 

3297.07 

10.5822 

6.61386 

4  =  0.6200 

43.055 

'4.784 

9.884 

4  =  0.06173 

61729.43 

14.1096 

8.81849 

5  =  0.7750 

53.819 

5.980 

12.355 

5  =  0.07 

rie 

7 

ri61.78 

17.6370 

11.02311 

6  =  0.9300 

64.583 

7.176 

14.826 

6=0.09 

259 

9 

>594.14 

21.1644 

13.22773 

7=1.03,50 

75.347 

8.372 

17.297 

7=0.10803 

108026.49 

24.6918 

15.43235 

8=1.2100 

86.111 

9.568 

19.768 

8  =  0.12 

546 

12 

5458.85 

28.2192 

17.63697 

9=1.3950 

96.874 

10.764 

22.239 

9  =  0.13889 

138891.21 

31.7466 

19.84159 

CUBIC. 

WEIGHT.—  (Continued.) 

s 

0 

2oj 

S 

0    . 

<" 

3  2 

02  +J 

•<£ 

S"~ 

fl      • 

J* 

P 

«§ 

II 

gS 

2^ 

la 

gg 

Ss 

~**2 

0^ 

S  . 

^-O 

Q^ 

tjS 

0-0 

31 

fcnJ 

So 

•5 

•o 

is 

P 

P 

S3 

§! 

o 

o 

0 

0 

a 

0 

1  =  0.0610 

61.023 

35.314 

1.308 

1=   220 

.46 

2204.6 

0.03215 

2  =  0.1220 

122.047 

70.629 

2.616 

2=   440 

.92 

4409.2 

0.06430 

3  =  0.1831 

183.070 

105.943 

3.924 

3=   661 

.38 

6613.8 

0.09645 

4  =  0.2441 

244.093 

141.258 

•   5.232 

4=   881 

.84 

8818.4 

0.  12860 

5  =  0.3051 

305.117 

176.572 

6.540 

5=1102.30 

11023.0 

0.16075 

6=0.3661 

366.140 

211.887 

7.848 

6=  1322 

76 

13227.6 

0.19290 

7  =  0.4272 

427.163 

247.201 

9.156 

7=1543.22 

15432.2 

0.22505 

8  =  0.4882 

488.187 

282.516 

10.464 

8=1763 

.68 

17636.8 

0.25721 

9  =  0.5492 

549.210 

317.830 

11.771 

9=1984 

.14 

19841.4 

0.28936 

INDEX 


Acids,  organic,  125 
A.fter-products,  195 
Alkalinity  of  sugars,  134-140 
Ash  in  sugars,  118-120 

Bagasse,  175-177 

Balances,  12 

Bates'  saccharimeter,  36 

Baumann's  method,  103-106 

Beet   sugar    determinations,   188, 

189 
Bone-black,     calcium     carbonate, 

145 
"          ,  calcium  sulphate,  146 

"     sulphide,    146 
,    carbon,    sand,    clay, 

145 
"         ,    decolorizing    power, 

148 

,  free  lime,  146 
,   iron   and   aluminum 

oxide,  147 

,  organic  matter,  148 
,  sugar  in,  148 
"          ,  tri-calcic  phosphate, 

147 

"         ,  water,  145 
"          weight,  149 
Burettes,  graduation,  13 

Cane  formulae,  184,  185 

"     juices,  170-175 
Cane-sugar,  determinations,  164- 

166 
Cattle  food,  200 


Cellulose,  133 

Chandler-Ricketts'  method,  74-78 
Clerget-Herzfeld  method,  71-73 
Coal,  analysis,  154,  155 
Coal,  properties,  153 
Coefficient  of  purity,  60-64 
Colorimeters,  26,  27 
Commercial  glucose  and  sucrose, 

74-78 
Conversion   factors,   polariscopic, 

32 

Corallin,  136 
Cosettes,  dry,  191 

"        exhausted,  191 

fresh,  190 

Cover  glasses,  47,  48,  69 
Cupric  oxid  method,  126-128 

Defecation,  dry  lead,  69 
Density   determination    of    solu- 
tions: 

by  balance,  24,  25 

araeo-pycnometer,  23 

glass  spheres,  23 

gravimeter,  22 

hydrometers,  21,  22 

Mohr's  balance,  23,  24 

pipette  and  beaker,  21 

pycnometer,  19-21 
Dextrose  and  sucrose,  74 
Dextrose,    levulose    and   sucrose, 

97-103 

Diffusion  and  press  juices,  191,  192 
Diffusion  waters,  192 
Double  dilution  method,  67 
305 


306 


INDEX 


Dry  lead  defecation,  69 
Dutch  standard,  55 

Errors,    possible,    in   polarization 

66-70 
Exponent,  determination,  60-64 

Fehling's  solution,  84 
Fill-mass,  180,  194 
Fill-mass,  composition,  206-209 
Fill-mass,  density  determination, 

204-206 

Filter-press  work,  177,  178 
Flasks,  graduation,  13,  14 
Flue-gases,  156 

Gums,  134 

Gunning-Kjeldahl    method,    132, 
133 

Home's  method,  69 
Hot  polarization  method,  74-78 
Hydrazones,  107 
Hydrochloric  acid,  158 
Hydrometers,  15-19 

Indicators,  134-136 
International  Commission,r4sume, 

217-236 
Invertase,  4,  71 
Invert  sugar  and  sucrose,  74,  90, 

94-97 

Invert    sugar,    gravimetric    anal- 
ysis, 87-89,  114, 
115 
"  "    ,    methyl  blue  test, 

110 

"    ,    raffinose   and  su- 
crose, 103-106 
"    ,    volumetric     anal- 
ysis, 85-87, 111- 
114 
Iron  oxide  in  sugar,  144 

Juice  formulae,  185-187 
Juices,  thick,  193 
"     ,  thin,  193 


Kjeldahl  method,  128-132 
Kjeldahl-Gunning   method,    132- 
133 

Levulose  and  sucrose,  78 
Levulose,    dextrose    and   sucrose, 

97-103 

Light,  sources,  48-50,  70 
Limestone,  152,  153 
Litmus,  135 

Lovibond's  tintometer,  27 
Lubricating  oils,  157, 158 

Measuring  apparatus,  graduation, 

13,14 

Meissl-Herzfeld  method,  94-97 
Methyl-blue  test,  110 
Molasses,  180,  181,  199 

Nitrogenous  substances,  126-133 
Non-nitrogenous  substances,  133, 
134 

Organic  acids,  125 
Organic  non-sugar,  124 
Osazones,  108,  109 

Phenol-phthalcm    solution,     135, 

138 

Phenyl  hydrazine,  107 
Phosphoric  acid  paste,  149-151 
Pipettes,  graduation,  13 
Polariscope  cover  glasses,  47,  48 

tubes,  46,  47 
Polariscopes,  29,  32-36 
Polarization,  29 

Polarization,  possible  errors,  66-70 
Precipitate  volume  error,  66-69 
Press  cakes,  193,  194 

Quartz  plates,  45,  46 

Raffinose  and  sucrose,  78-81 
Raffinose,      invert      sugar      and 

sucrose,  103-106 
Raw  sugar,  195-199 
Refinery  determinations,  202-204 
Refractometers,  5-12 


INDEX 


307 


Rendement,  209-212 
Rosolic  acid,  136 
Rotation,  specific,  30-32 

Saccharimeters: 

adjustment,  examination,  39-44 
Bates',  36 

double-wedge,  34-35 
graduation  temperature,  70 
scales,  37-44 

Soleil-Ventzke-Scheibler,  34 
Solids  and  liquids,  weights,  25,  26 
Sources,  light,  48-50,  70 
Specific  rotation,  30-32 
Sucrates,  4 

Sucrose,  alpha  naphthol  test,  82 
Sucrose  and  commercial  glucose, 

74-78 

' '       and  dextrose,  74 
"        and  invert  sugar,  74,  90, 

94-97 

"       andlevulose,  78 
' '       and  raffinose,  78-81 
' '       by  chemical  analysis,  82- 

93 

"        by  optical  analysis,  51-81 
"        by  optical  and  chemical 

analysis,  94-106 
' '      ,  composition,  1 
*'*      ,  destruction  by  heat,  3 
"      ,  determination  as  invert 

sugar,  82-89 
' '      ,  dextrose  and  levulose,  97- 

103 

' '      ,  formation,  2 
' '      ,  in  absence  of  other  opti- 
cally active  substances, 
55-70 

"      ,  in  condensation,  boiler- 
feed  and  waste-waters, 
64,  65,  89,  90 
,  in  fill-mass,  64 
' '      ,  inversion,  3,  4,  84 
1 '      ,  invert  sugar  and  levulose 
or  dextrose,  90-93 


Sucrose,    invert   sugar    and    raf- 
finose, 103-106 

"      i    in    presence    of    other 
optically     active     sub- 
stances, 70-81 
loss,  215,  216 
loss  formulae,  187 
,  production,  1 
,  properties,  1-4 
,pure,  18,19 
,  solubility,  2,  3 

table,  285,  286 
Sugars,  acidity,  140,  141 
' '    ,  alkalinity,  134-140 
';    ,  analyses,  reporting,  212- 

215 

11    ,  analysis,  178,179 
Sugar  ash  analysis,  121 
"      beets,  190 
"      cane,  166 
Sugar  cane,  fiber,  169,  170 

' '    ,  sucrose,  166-169 
"      sampling,  51-55 
' '      solutions,  refractive    index, 

10,  11 

Sulphur,  157 

Sulphurous  oxide  in  sugar,  141 
Suspended  impurities,  122,  123 
Syrup,  175 

Tables,  237-303 
Thermometers,  27,  28 
Tintometer,  Lovibonds'  27 

Water  Analysis,  158-162 
Water,  determination,  115-118 

,  improvement,  163 
Waters :  condenser,  boiler-feed  and 

waste,    181-183,     200, 

201 

Weights,  12,  13 
Woody  fiber,  123 

Yield,  209-212 


M503715 


•33 


